How to lose weight rapidly

fat to skinny with healthy diet weight loss

Over the last year I’ve written several articles about how to lose weight, what the studies show works and what they show doesn’t work. I figured it was time to put all that content together in to a single article that makes clear actionable recommendations. First, let’s just get one thing straight – the most commonly offered advice, to eat less and exercise more, doesn’t work. At least not for the vast majority of people.

When people begin the “eat less, exercise more” diet they quickly start to feel like they’re starving to death. At the same time, their metabolism slows to a crawl, which results in much less weight loss than would be predicted based on how much less they’re eating. It’s only a matter of time before they break down, and when they do, they’re likely to end up weighing even more than they did to begin with.

A successful weight loss diet isn’t one where you’re consciously counting calories and just eating less of the things you were eating before. It’s one where you completely overhaul what you’re eating. There are two different ways in which this can be done, both of which work. The first is to significantly increase protein intake. The second is to significantly increase fibre intake. Both work. If I wanted to lose weight rapidly, I’d do both simultaneously.

Earlier this year I decided to do a personal experiment with switching from the paleo-ish diet that I normally follow to the pure animal product carnivore diet, just to see what would happen. What this meant in practice was cutting down dietary fibre from around 50 grams per day to less than 10 grams per day (by getting rid of all the berries, nuts, and vegetables I was eating), while increasing protein from around 17% of total calories to 30% (by eating more meat). What happened?

Actually, I rapidly gained weight, from 73 kilograms to start to 80 kg around a month later, which is more than I’ve ever weighed (although still within the limits of what would be considered “normal weight”). Considering that I’m normally stable at 73 kilograms with little variation up or down, this was a pretty profound change and could only be explained by the change in diet. The weight remained stable at 80 kg for a few months, until I reintroduced fibre, at which point it dropped down again.

That is of course entirely anecdotal evidence from my self-experimentation, so the findings should be taken with a grain of salt, but it showed me how much of an impact fibre has on body weight, which would explain why people in cultures with traditionally very low intakes of protein, such as the people of Okinawa and the Kitavans, can still be slim. It suggested to me that fibre might actually be the more powerful of the two levers to pull on. That would be an interesting topic for future research.

That being said, there is no reason to do just one or the other when you can do both at the same time (unless you have some gastrointestinal issue and aren’t able to tolerate high fibre foods, or you’re vegan, say, and therefore can’t access the densest sources of protein – in that case it should be perfectly possible to achieve success by just doing one or the other, it might just take a little longer to get where you’re going).

So anyway, there are two levers you can pull on if you’re overweight and your goal is to lose weight. Most people in the western world have a low protein intake, at around 12 to 14% of total calories. They simultaneously have a low fibre intake, at around 15 to 20 grams per day. If you’re currently normal weight and you want to avoid gaining weight over time then you can probably get away with going low on one, but you can’t go low on both.

People with functioning kidneys can safely get as much as 30-40% of total calories from protein, which if you’re overweight will result in rapid weight loss. The average person can also easily increase fibre intake to 50 grams per day without negative consequences, although the fibre intake should be increased gradually, over the course of a few weeks, or there is likely to be some stomach pain and diarrhoea while the body adjusts to the increased fibre.

There is one class of food that is particularly detrimental to body weight, and that is refined carbohydrates. Refined carbohydrates are low in both protein and fibre, and they are therefore optimally designed to make you gain weight. Pure fats, such as butter and oils, are also low in both protein and fibre, and intake of them should therefore also be kept to a minimum.

Note that I’m not saying you should necessarily eat a low fat diet. What I’m saying is that you should limit intake of pure fats if your goal is to lose weight rapidly. A little butter in the frying pan is fine, but eating a stick of butter isn’t.

In light of all of this, an optimal weight loss plan has three pillars.

  1. Increase protein intake to 30-40% of total calories.
  2. Increase dietary fibre to at least 50 grams per day.
  3. Avoid refined carbohydrates and pure fats.

If you’re overweight and you do all these three things, then the excess weight will rapidly come off. You don’t have to feel like you’re starving. And you don’t have to count calories. You just have to make sure you’re getting sufficient protein and fibre.

Here are some examples of foods that are high in protein:

Tuna (85% of calories)
Chicken breast (75% of calories)
Cottage cheese (70% of calories)
Low-fat Greek yogurt (70% of calories)
Beef steak (50% of calories)
Soybean (50% of calories)
Pork chop (45% of calories)

And here are some examples of foods that are high in fibre:

Cauliflower (16 grams per 100 calories)
Raspberries (13 grams per 100 calories)
Broccoli (12 grams per 100 calories)
Spinach (10 grams per 100 calories)
Asparagus (9 grams per 100 calories)
Cabbage (8 grams per 100 calories)
Strawberries (6 grams per 100 calories)
Chickpeas (5 grams per 100 calories)
Kiwi (5 grams per 100 calories)
Avocado (5 grams per 100 calories)
Blueberries (4 grams per 100 calories)
Sweet potato (4 grams per 100 calories)

And here’s a list of foods that should be avoided like the plague if your goal is to lose weight rapidly:

Soft drinks
Alcoholic drinks
Ice cream
Corn (maize)
Anything with added sugar

There are many different ways you can eat that will accomplish the dietary goals of getting at least 30% of calories from protein and at least 50 grams of fibre. If you, for example, get 50% of calories from high protein foods and 50% of calories from high fibre foods, then both goals should be fulfilled without too much difficulty. Here’s just one example of what a daily meal plan might look like:

Breakfast: Low fat Greek yogurt with blueberries and raspberries

Snack: Kiwi

Lunch: Chicken breast, sweet potato, and broccoli

Snack: Cottage cheese

Dinner: Steak, sweet potato, and asparagus

(I hope you like sweet potato!)

Don’t attempt to limit overall portion size. Eat as much as you need to in order to feel satisfied at each meal.

Just as a final clarification, if you’re already at your ideal weight, then you don’t need to go up as high as 30% of total calories from protein or 50 grams of fibre. You can get away with less of both without gaining weight. This is for people who are overweight and want to lose weight rapidly.

That’s it. No need to read anything further on the topic of weight loss. Just follow this advice. I hope this is helpful to people. If you decide to try part or all of this, then let me know how it goes!

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82 thoughts on “How to lose weight rapidly”

  1. Excellent content as always. Curious though, as to what you think of the conclusions of Fat Fiction, the documentary that also praise fat for weight loss (unless I misunderstood their conclusion).

  2. Hi doc, I don’t know how active you are on Twitter so I’ll repost my comments here.

    I’ve been reading your content this past year and really enjoy it. Keep it coming! I have a question and a comment.

    Q: you mentioned gaining 7kg since going carnivore, but do you know how your % body fat changed? if you do, I’d love to know if/how it did.

    High-fiber diets for fat-loss is called Volumetrics, essentially. Its been around since 1990s via Barbara Rolls. It seems like a failed approach; no RCTs support it & although fiber does make you put the fork down sooner (i.e. increases satiation), it won’t do anything for your satiety (i.e. delay eating again).

    In essence, it’s ‘trick’ for calorie restriction. In your article you say that calorie restriction (eat less, move more) fails, yet you say this indirect way to restrict calories works. I think there is a contradiction here. You may think there isn’t; could you say why please?


    1. I’m afraid I can’t answer the first question, since I didn’t measure that.

      Fibre doesn’t work by restricting calories. Total calorie intake is usually the same on a high fibre diet as on a low fibre diet, it just isn’t accompanied by the same weight gain.

      I agree that the human studies of fibre are generally pretty low quality, although they overall suggest that fibre is effective at lowering weight, and there is plenty of observational data in support of that notion, such as that coming from the Okinawans and the Kitavans. There is however plenty of experimental animal data that shows that high fibre results in lower weight.

  3. Hi, interesting summary. A few notes
    Crisp must mean sugary fruit dessert.
    Chips may belong to your avoidance list?

    Ted Naiman has put it very nicely:
    – If you want to burn more fat , eat less carbs
    – If you like that fat to come from your adipocytes (ie Loose weigth), eat less fat.

    This results in increased protein, as to your direction.

    I would and I DO avoid pufas on bottles and in processed foods. Their final metabolism is different satiety wise, being able to pack energy in cells and avoiding Ros signaling. Not to mention the unique poisons like 4hne, they can peroxide to. Looks like the body is not adjusted to burning massive omega6 loads in just 100 years.

    1. I think Ted Naiman has actually come around to the alternate way of thinking, that it’s the increase in protein that drives the weight loss, no the decrease in carbs. At least that’s the impression I’ve gotten from recent interviews with him I’ve listened to. And that aligns better with what the experimental data shows.

      1. Thank you for your response, dr. Rushworth. You are to the point, let me qoute dr. Naiman again from an article “and I think you get a higher satiety per calorie when you increase protein and fiber, and when you decrease refined carbs and and refined fats. I think that’s really what it’s all about.”

        Another one “Naiman notes that adding high protein foods to the diet actually make eating fewer carbs and fats easier. He explained that humans are programmed to eat until they have consumed an adequate quantity of protein—even if that means they have to significantly overeat carbohydrate and fat energy to accomplish that.”

        Interestingly, he has joined Dietdoctor and they are moving towards more protein!

        Thanks to Vannie for crisp, chips and fries explanation.

      2. That is exactly right. We are programmed to keep eating until we’ve reached our protein set point, as are most other animals. So if we eat a low protein diet, then we ingest more calories before we hit the set point and stop eating.

        Yes, Dietdoctor is also following this evidence and transitioning from low carb to high protein.

    2. In the UK “crisps” is what Europeans call “potato chips” – the flat, crunchy, dry, fried, thin slices of potato, usually salted or otherwise flavoured that are bought in a sealed bag.

      Confusingly, in the UK “chips” are what Americans call “French fries”.

      So “crisps” aren’t sweet desserts.

      1. Neither to confused with the quite healthy “rye crisps” (knäckebröd) from Sweden 🙂

  4. I think here too we are not all the same. For some, eat less move more may still work quite well. After a while the feeling that you starve goes away or you just get used to it. You need to have some pretty intense activity maybe to keep your metabolism going. Above all, for many of us te first very important step (and even the only necessary one if you don’t need to lose weight fast) is to cut out all the junk full of sugar.

    1. …and cutting out alcohol. That’s my issue! I know I can do it as I have done before, but this couple of years has really stretched my resolve!

  5. It seems to me that a high fiber diet reduces fat absorption. So why not just eat fat in meals as long as you get a high dose of protein? Moderate cheese + fiber shouldn’t be a problem.

    You get lots of vitamins with oils and fat. As long as fiber carries them through the gut without much fat uptake, maybe you’ll increase your vitamin benefit with fats and oils.

    Also, the skins of fruit and vegetables contain most of the nutrients, so look for products that contain veg. skins.

    Don’t soybean components decrease male testosterone?

  6. Thank you again Dr Rushworth. Good and interesting read as always.
    I follow a slightly different approach that has worked well for me.

    Essentially a diet with low-carbs, high protein and high fats plus intermittent fasting.
    Similar but less strict than keto.

    Carbs, mainly from low carb/high fibre+protein bread.
    Fats, I use olive oil, MCT, coconut and butter.
    Then on top of that whatever meat and vegetables I prefer for the day.
    Coffee with some MCT+butter.

    Typically 18-20h fasting per day, sometimes longer and sometime shorter (for example if theres a family dinner or something extraordinary).

    I don’t know if fasting actually reducing the total amount of food/calories over time, probably it does and if so it’s likely the main reason for loosing weight. But I think high fat + protein diet helps with the fasting and to maintain a constant low blood sugar level as I rarely feel hungry.

    My glucose / ketons are around 4,0 / 0,8 mg/l after 20h fasting.

    Anyone interesting in this kind of diet, check out Dr Sten Ekberg and Dr Eric Berg on youtube.

    I will read your article again in the next few days to think again if I can optimize my diet a bit.

    1. My approach is exactly the same as yours, except I do not have any type of cereal or bread. I don’t have milk as it is pasteurized and I don’t feel well after having it, nor neither of its substitutes like soy milk, almond milk, etc. I don’t have any of those.
      I don’t have sugar nor substitutes.
      But I have meat with its saturated fat. I usually cook my meat in extra virgin olive oil or organic coconut oil. I dress my salads with olive oil. I have plenty of almonds every day, and olives and avocados, etc. So, I am not afraid of fats at all, I just don’t have trans fat or seed oils.

  7. I was diagnosed with Type 2 diabetes a couple of years ago. I simply stopped eating anything with ADDED sugar (includes Dextrose, Glucose, Maltose, Lactose etc) and I lost 10 kgs. I still eat heartily & healthily – never feel hungry. The biggest problem is buying food which doesn’t have added sugar – almost everything on a supermarket shelf has added sugar, but after a month or two of looking at labels, you become used to those without sugar.
    PS HBA1C dropped from 53 to 48

    1. If you eat real, unprocessed food you won’t find sugar on the label. Obviously fruits has fructose in, but by choosing those with lower amounts and higher fibre (eg berries rather than bananas) you can still limit the amount of “sugar” you ingest.

  8. Hello doc, where does cheese fit in this? It has protein but I believe it’s usually recommended to avoid or moderate it to lose weight? Thanks

  9. Hi everyone,

    I am 56 years old and weigh exactly the same as I did when I was 18, namely 7 stone 7 ounces (circa 47 kg). My height is 1 metre 58 cms so this is average weight for my height. The reason: the diet Sebastian describes! It works and I am living prove of it!

    At secondary school my nickname was The Gannet as I used to eat not just second helpings for cooked school dinners but go up for third heloings of protein and vegetables and carbs. Other nick-names were Hollow Leg.

    What did we eat at school and what have I eaten all my life? Plain fish, eg cod or tuna; boiled cabbage with black pepper and butter; boiled potatoes sprinkled with chives; kale, sprouts, carrots etc. Fish thrice a week. No cooked puddings, just bananas, apples and oranges. Not exciting but not fattening and the meals gave plenty of fuel.

    To conclude, I have always eaten the diet Sebastian advises except in my final year at university when – you’ve guessed it – I ballooned on a diet of coca-cola and too many sugary snacks whilst I was revising. I duly passed my exams, ditched the coca cola as I no longer needed to revise all night and my weight returned to normal after two months and has been the same ever since part from putting on a stone when I was pregnant.

    On preganancy: a few imparticla observations…. I was EXACTLY my normal weight upon giving birth. I did not have to lose any. If anything I had lost weight as I was also weighed down with breast milk. I did not change my diet when pregnant; I did not have cravings and I continued to cycle up uptil I was 7 months pregnant.

    (My aunt Suzanne was the same and my Godmother Andrei, so the fact that all three of us only put on the weight of our newborn – 7 ounces of baby and 7 ounces of amniotic fluid suggests there may have been a genetic factor or our diet. My mother did put on a lot of weight – two stone when pregnant with me but she also lost it quickly without having to try which suggest her food intake was the key).

    Lastly, both my children, now aged 27 and 30 respectively plus my 62 year old husband Paul, all have remained the same weight since adulthood without trying excpet from the “university bulge” at revision time!

    So I am 100 per certain that Sebastian is correct in his observations : a balanced diet – with protein for energy and vital lipids for the collagen as one ages means one does not put on weight or get any joint-ache etc.

    I personally am not on any medication for anything.

    Warmest regards,
    Chantal Ashby Heaven

  10. Wot, no mention of fish, doc (except tuna)? No mention of bananas, apples, pears, oranges, grapes …
    (I find some modern varieties of grapes horribly sweet: “Cotton Candy” grapes are particularly vile.)

    On protein: it used to be argued in Britain that you could eat too much protein – a problem, purportedly, of families in the countryside who ate too much rabbit.

    Anyway, as ever, thank you for your writing.

    1. To be fair, he did give those as examples. However, I personally avoid Tuna due to the potential mercury content.

      As for bananas and grapes specifically, as far as I’m aware they have a high glycaemic index and therefore high “sugar” content and little fibre. I think he’s deliberately avoided mentioning fruit as you can get all the nutrients available from them in fresh vegetables but without risking too high a sugar intake. Berries like raspberries, strawberries, blackberries, blueberries are the ones usually recommended on such a diet as they have a better fibre to fructose ratio and don’t increase insulin levels like many other fruits. In addition, part of the idea of cutting out “sugar” is to retrain one’s taste buds to accept a less sweet diet overall, which is more difficult if you continue to eat fruit.

      What sort of problems did the rabbit-eaters suffer from, out of interest?

      1. Maybe what they call “Rabbit starvation” or “protein poisoning”?
        Basically when you eat too much protein and nothing else and you’ll essentially be starving due to eating no fat and other important nutrients.
        Rabbit meat is extremely lean.

  11. Hello from Italy and congrats for your blog!

    Being Italian I might be biased.
    I see you suggest to avoid pasta if you want to loose weight fastly.
    Wholewheat pasta is rich in fiber (2,5 g per 100 calories) and still a souce of proteins (3,5 g per 100 calories).
    It’s also important to eat pasta “al dente”, so no extra-cook. It mantains low the glicemic index (white pasta differently from white bread, if eaten “al dente” still has a low glicemic index despite being refined, but missing fibers).
    In general whole wheat cereals were the base of the Mediterranean diet.

    So saying Pasta (or wholewheat Rice and other cereals) has to be avoided like the plague it seems to me exaggerated (if not wrong)

    1. I don’t think it needs to be avoided if you’re at a weight you’re happy with, only if you want to lose weight as quickly as possible. With 2.5 g per 100 calories, it would be hard to get to 50 g total, assuming you’re also trying to reach the high protein target.

    2. As an Italian I must agree for the most part with Paolo’s comments. I think Italians in general are more aware of what they put in their mouths and in what quantity.That makes a difference. Food is an important topic among Italians. Living in the United states has made me aware that most Americans are not aware. Italians grow up understanding food and often making their own meals while here in the USA nutrition isn’t taught anywhere and many Americans can’t read a nutritional label . Close to 80% of American groceries are stocked with the very foods you warn us not to eat, proof that in USA its all about profit and not nutrition. Another issue is that the bad foods you mention do raise blood glucose levels and can lead to Type 2 diabetes which is epidemic.

  12. Hello Doc Rushworth. What’s your opinion on eggs? From what I understand, one has to be careful as to how many they eat on a regular basis due to creating an allergy to eggs. And what’s your opinion on regular potatoes either baked or boiled? We try to eat what grows well here, which is potatoes, brassicas, alliums, leeks, blueberries, and apples.

    I’d love to know what your opinion is on how hormones play a part in weight gain. I am now in menopause and find it extremely difficult to keep from gaining weight. I have also found that if I don’t drink enough water I tend to gain weight.
    Your insights are appreciated.


    1. I think potatoes are fine if you’re at your ideal weight, but a little low in fibre if you want to maximize weight loss. Eggs are also fine if you’re at your ideal weight, but a little low in protein (30%) if the goal is to maximize weight loss.

  13. Hi Sebastian. Really interesting as always. Could you please link to a list of protein foods with their percentages? I couldn’t find one. Also to high fibre foods. All the lists I could find were per 100g. Thanks, Jessica

  14. I have found that eating certain full fat foods (yogurt for one) leaves me satiated with less food than eating a low fat version. Plus it tastes better.

    1. I agree with Jeffrey Herrmann. Your suggested diet looks great, but is it really necessary or even beneficial to go with “low fat” Greek yogurt rather than full fat Greek yogurt?

      1. Not if you’re at your ideal weight already. But if you want to lose weight as quickly as possible, then the best way to do that is to maximize protein, which is most easily done by going with low fat options.

  15. The human body comprises 38 essential vitamins and minerals. Fortunately Dr Rushworth’s suggestion hits most of them.
    What’s often excluded on the subject of achieving a normal BMI is the mechanism of the Krebs (citric acid) cycle.
    It is nice to see suggestions to reduce phytic acid, linoleic acid, gluten etc. starting to emerge in dietary advice.

    I think the “secret” to achieving a normal BMI is genuine nourishment.
    Unfortunately most people don’t understand nor even comprehend the paradox that is their malnourishment.

  16. I agree on all except one point or item. Have full fat Greek yoghurt. I think all diets that are based on anything low fat will set you up to fail. Fat helps satiety and stops you reaching for ‘naughty’ sweet things. I decided to drop my carbohydrate levels after finding myself in the pre-diabetes zone. I weighed 9 stone 7 and had a BMI of 22. I upped the fat content and fibre and I lost 21 pounds in 3 months. I have slowly introduced carbohydrates. My rule is no white carbohydrates only brown. I managed to pull back out of the pre diabetes zone.

    1. Hmm, that’s a good question that I haven’t really thought about. My spontaneous answer would be fruit juice, but the problem there is that it’s high in fructose. Maybe pure glucose solutions would be the least bad way to rapidly gain weight, although that will spike insulin. An alternative strategy would be pure fats, like whipping cream. The most effective strategy would probably be one that combines both carbs and fats.

      1. There are now jolly good alcohol-free/low alcohol beers on sale. They presumably provide a particularly palatable source of calories without the risk of taking too much alcohol.

  17. What do you think about eating at fewer intervals in the day in order to reduce the frequency of insulin secretion , the fat storage hormone, and facilitate the burning of fat?

  18. I have tried many diet variations over the years. Paleo, keto, Atkins, etc. I am 56 and very active. I have maintained my weight between 125-130 lb with around 22% BF. These last four months, I have been using a macro based program and would highly recommend. With the program, I do keep my protein levels at 1 gram/lb of weight, so around 125 grams/day. My carbs can be anything but I stick with high fiber options such as sweet potatoes, berries, vegetables and some rice. Protein is mainly grass fed beef and organic chicken with some fish. My fat intake is limited but I do have yogurt, chicken thighs, salmon and use oils or butter to cook. I stay away from processed foods and cook almost all of my meals. Trying to stick to a plan with processed foods is nearly impossible. I can say that my health markers have improved with more fiber than the other diet options. My weight hasn’t changed much but my fitness has improved as well as my overall energy levels. I think for someone wanting to lose weight, counting calories and macros is important. We can get lost in the data sometimes, but most people have no clue how much to eat or really what to eat. Macros can provide a guide to many to stay focused on a plan to improve their chances of success.

  19. Does speed of eating and mindfulness play a role?
    I am a very fast eater and was able to lose weight quite fast by starting to pay attention to hunger signals (instead of eating emotionally) and putting my fork down between bites.

    I kind of remember a paper showing weight loss by training people to eat slowly and purposefully.

    It is nicely orthogonal to the rest of your very good advices though.

  20. Having been a vegetarian for 38 years, a non-smoker all my life and a daily jogger it came as a shock when I was carted off to hospital in an emergency ambulance with a BP reading of 213/111 and a pulse around 44 bpm. I was told that my chance of a heart attack/stroke was 1 in 3. I was prescribed statins (which I never took). Seeing what Malcolm Kendrick, Ivor Cummins et al had to say about statins etc. I adopted a HFLC diet and began eating fatty meat, butter, etc. Within two months I had lost 2st 4lb (losing weight wasn’t my main intention) had a flat stomach with my BP down to 140/78 and falling. In my case eating cheese and butter and streaky bacon reduced my appetite to the point that I began to lose too much weight, regaining it when I began eating peanut butter.

    What is of concern is the idea that fibre is good for you. I listened to a lecture by Dr. Paul Mason, who suggested that the evidence is that fibre is unnecessary and possible not good for gut health. I’ve yet to make my mind up on that one.

  21. We’re going to have a large crop of Jerusalem Artichokes for this winter, which we tend to eat as soup, combining them with an equal weight of potatoes and a little bit of bacon. Is that a decent fibrous lunch?

  22. I am at a good weight, and just want to maintain it.

    I have found one meal a day (treat it like a satiating calorie/nutrient dense feast) to be the easiest approach to doing just that. It is also easy to lose weight in a very controlled fashion by turning the dial down on the sweeter items (dessert side).

  23. A discussion of setpoints would be helpful. Due to homeostasis, one’s bodyweight tends to remain within a few pounds of a median number. After determined dieting, the bodyweight may find a new setpoint that is often 10 pounds below the original. Further dieting may uncover a third setpoint that is even lower.
    There has been speculation regarding these points. Are they Fibonacci numbers? How do they work? To diet effectively one must find a lower setpoint where bodyweight stabilizes.

  24. Didn’t you say that keto diet is the most healthy and wouldn’t sweet potatoes take you out of ketosis with its relative high carb content?

      1. What about the hormonal regulation of weight loss – Wouldn’t eating carbohydrates spike insulin which is an anabolic hormone that upregulates lipogenesis and weight gain? I thought the idea of keto is to keep insulin as low as possible so that fat isn’t created and deposited?

        On another note would you recommend a low carb recipe book?

  25. Thanks Sebastian,
    brilliant as usual, this really hits the nail on the head.
    It’s what I practice and tell patients to do.

    Keep up the good work.

  26. Hi,
    How many pounds or kilograms is it safe to lose each week? Can one lose too much weight too rapidly?

  27. Thank you. Super interesting article.

    Consistent with my own experience. I weighed over 100 KG in late 2019 with a BMI circa 29. Am now 77 KG with BMI of 22 that has been roughly constant for a year.

    I did not take a very scientific approach to the diet change but what I did was to remove carbs (especially chocolate, juice and bread) and substitute more salad / fruit plus eat more fish. Did not measure calories at any point but it seemed to work.

    Still not sure I understand the full drivers of why this works! I saw a very good video by Giles Yeo that seems very consistent with this article. However, he does highlight restricted calories along with high fibre and high protein as the elements (not necessarily all together) that form part of a weight reducing diet.

    Clearly, there is circularity. We have to eat something. So the high fat diet that gets talked about might work because eating fat tends to be accompanied by eating high levels of protein! A plant based diet may have low levels of protein but there is only so much fibre one can eat so potentially that works too. Although one does wonder how sustainable it would be from an overall health perspective if one does not eat protein too.

    With respect to carbs I think I am learning that the issue with eating a high carb based diet is that one over consumes them because they are highly calorific in relation to bulk (unlike plant based food) and low in protein. So the temptation is to overeat. I might restrict my calories on such a diet but will always feel hungry so ultimately I will give up and revert to old practices. This might explain why traditional “dieting” does not work long term.

    What does shock me is how unclear (and even wrong) the guidance around this from governments and public health bodies actually is. My guess is that (as with Covid) they are heavily compromised by corporate interests that provide funding and jobs. Some of these interests want to sell the low fibre, low protein but high sugar processed food that seems to be the root cause of much of our so called obesity crisis. Others then want to sell “remedies”. Not a conspiracy to defraud anyone but just an outcome of incentives.

    Would welcome your views on whether my understanding is broadly correct. I keep coming back to the idea that restricted calories must be part of the mix (just as a logical outcome) but targeting the calories does not work. One needs instead to target the mix of food that is consumed. The idea too that the body targets a certain level of protein input is also very interesting.

    Thanks again for a great article. I also bought your book about Covid. It’s a great read.

    1. Thanks. I think you’re pretty much spot on with your analysis. Calorie restriction happens automatically with a high protein diet, since protein intake is the primary factor controlling appetite and calorie intake. We’re designed to not overeat protein. Therefore calorie restriction doesn’t need to be attempted consciously. The scientific term for this is ”protein leverage”. It’s been well established that protein is the primary driver of appetite in both humans and many other species for years now, so it’s pretty remarkable that many nutritionists still don’t seem to be aware of it and that it isn’t reflected in official guidelines.

      1. Thank you for replying.

        This now makes total sense.

        Amazing that most “guidance” is so wrong!

  28. As an addition to my earlier comment, this motivated me to read the UK NHS dietary guidelines.

    They are couched almost entirely in terms of calorie control.

    There is what I believe is a good recommendation to eat 5 portions of fruit and vegetables per day.

    Fruit juice is acceptable though (in their view) as one of these portions.

    They then advise people to eat starchy foods such as bread and rice.

    Dried fruit is also recommended with cereal for breakfast! Dried fruit is low fibre, I believe, so this does not feel a smart suggestion.

    Lots too of the normal advice against eating fat, which may make sense but is less relevant if eating fat is accompanied by protein, and recognising that one has to eat something.

    Protein itself is not even mentioned. Red meat is “bad” though.

    Cholesterol seems to be a big concern for them too.

    The guidelines actually seem to be written in some areas as a manual for how to increase weight.

    Apparently, the full diet plan has been downloaded 2 million times though.

    I do wonder what so called “science” this is all based on but it may be the same “science” that is behind masks and lock downs.

    Am even less confident now that the medical mainstream knows what it is doing than I was previously.

    No substitute for reading diverse opinions and making ones own mind up! This blog is super helpful for enabling that.

  29. Obesity is a distraction and downstream from the real problem. If obesity was associated with longevity and healthspan perhaps we would all rather be obese. Health risks stem from insulin resistance, diabetes, metabolic syndrome, inflammation, etc. and this is caused by unhealthy behaviors, mainly excessive insulin production stimulated by a diet dominated by high glycemic carbs. Half the population is on the insulin resistance/prediabetes spectrum and it has been clearly shown that insulin itself induces insulin resistance. Adopt behaviors that corrects insulin resistance and the obesity epidemic will disappear. i.e. low carb high fibre diet with adequate protein, aka a fasting mimicking diet.

  30. “Eat less” – more precisely calorie restriction works very well. It was proved unintentionally (sic!) by Biosphere 2 project (Interesting reading – “Calorie restriction in Biosphere 2”). The issue with eating less is potentially less vitamins and minerals uptake. So one need to eat very good quality of food and/or supplement vitamins and minerals before restricting food intake.
    Higher protein uptake switches off autophagy so one can loose weight but without biggest health advantage of loosing weight (or fasting) so it does not make much sense.

    1. Biosphere 2 is hardly representative of reality. If you put people in concentration camps and don’t feed them anything they will lose weight. That tells you nothing about whether a weight loss strategy works in a setting where people have free access to food.

      The claim that a high protein diet is harmful to health comes from looking at surrogate markers. It is not supported by the actual hard outcome data.

      1. Its hard to compare this to a concentration camp. In concentration camp human health deteriorates. In Biosphere 2 their health were constantly monitored and all were better and better – people with different age and sex. And there were only volunteers there.
        I do not think they will be more comprehensive (high budget) study on this soon because nobody can make business with advising people just to eat less. However, there are a lot of animal studies on this.

      2. But no additional food was brought in to the biosphere, so they had to make do with what they could grow, and they were never able to grow enough to meet their needs, which is why they came out of the biosphere looking like concentration camp survivors.

        The claim that their health improved is based on the fact that blood pressure and so on improved. I think this is a case of mistaking surrogate outcomes for real world outcomes. Prisoners in world war 2 concentration camps probably also saw reductions in blood pressure, which is normally seen with weight loss – that doesn’t mean they were getting healthier.

  31. My mother essentially follows this (high fibre/protein) and she’s still significantly obese. Typical meal is turkey, apples, carrots, kale and maybe a rice cake. She is mostly sedentary (has always loved to read). I feel like something has to be completely out of whack biochemically. Any ideas?

    1. There are metabolic diseases that can cause obesity, such as Cushings disease and hypothyroidism. Although at least nine times out of ten obesity is caused by a bad diet. Definitely worth getting rid of the rice cakes!

      1. Sure, my mother can get rid of the rice cakes, but I highly doubt they are her problem, since they are mostly air. 🙂 She has seen endocrinologists most of her adult life, and no one seems to have any ideas. She does have hypothyroidism but is “lab stable” wrt hormone levels. Sadly, I think her doctors assume she eats boxes and boxes of Twinkies every day, but I can vouch for the fact that it isn’t the case. My father does all the shopping, and I lived in her house for 18 years and would have seen her doing so.

  32. Hi Dr. Rushworth,
    What if the breads, rice, pasta, etc. are whole grain? Do you still have to avoid them because whole grains have quite a bit of fiber?

    1. Whole grain bread and pasta are much better than refined, but often still quite low in fibre when put in relation to their calorie content. Often breads marketed as whole grain are really only partly whole grain and mainly refined grain while also having added sugar or syrup. If you look at the label and it’s 100% whole grain and there’s no added sugar or syrup, then that might be ok, although even then the fibre content is often quite low when put in relation to the calorie content.

  33. Well, good post except for the “fat issue”.

    I would say that:
    Be careful with Omega 6 fats! Must be kept low!!!
    Try to eat sufficiant Omega 3 fats!
    Do NOT avoid butter, cream, fat cheese, full fat fermented diary products. Dont avoid fat parts of meat. Taking them in “balanced” quantities helps you avoid bad stuff as sugars, “fast” carbohydrats and poisonous omega 6 fats. It will help you manage several hours between the meals and i.e. 16/8 fasting.

      1. I agree that fat isn’t harmful overall and that dairy fat doesn’t cause heart disease. The recommendation to avoid pure fats has to do with the fact that they are low in both protein and fibre, which an optimal weight loss diet should seek to maximize.

      2. “avoid pure fats”


        “take an appropriate amount of fat” (for the vitamins)?

        K2 is in dairy fat, for example.

        Is there evidence that some fat is adsorbed by fiber and carried through the gut without making it into the blood? So maybe we need to know fat adsorption per gram of fiber and calculate how much fiber we need if we are trying to stay healthy and still burn bodyfat?

  34. I got an ulcer when I was 21. Spent years eating small high fat meals supplemented with antacids. Weight was not a problem – gained 45lb in each of 3 pregnancies and lost it when I stopped breast feeding. Then came cimetidine for 10-12 years. Then treatment for helicobacter. When I relapsed after 2 years, the doc treated both me and my asymptomatic husband. Now clear for 20 years, but I still eat lots of fat and am stable with a BMI of 26.

    The trick is food prepared at home. If you don’t spend on take-outs and restaurants, you can afford to buy the best meat and vegs.

    1. There have been claims that a high protein diet is harmful to the kidneys generally, but this has been debunked. There is evidence that a high protein diet can be harmful in people who already have kidney failure, but for people with functioning kidneys it’s safe.

  35. I’m again and again surprised by the fuzz about diets. I am a pretty healthy and athletic 52 years old male. My BMI is around 20-21. Hasn’t really changed in 30 years. I’ve never cared about any sort of diet. I simply buy very good food and cook each and every single day. By that, I don’t mean just the fancy-schmancy organic stuff. Any kind of processed food is a no-go for me, let alone junk food. Sugar is ok, but I use so little of it that it is really not significant. We are talking about, say, less than a kilogram per year (as pure sugar).

    Now to excercising: It doesn’t work? Sure, it does! However, an obese person won’t benefit from your grandmother’s sunday morning workout. While serious excercising can be fun, it means blood, sweat and tears.

    I usually lose 3 to 4 kgs weight in 14 days on my hiking trips. This is not a miracle. I eat more or less the same (or even a bit less) while burning 5000 to 7000 calories per day. That’s a negative energy balance. It’s simple as that. Is there a yo-yo effect? Not really. I could keep that weight, but notice: We are talking a BMI of 20 or 21, not 45!

  36. I think Paul Mason was talking about insoluble fibre (basically cellulose) and not about insoluble fibre which acts as food for beneficial bacteria.

  37. About 15 weeks ago I decided to take the advice of this article. I targeted my protein intake to about 40% of my daily calories and my dietary fiber (I’m American) to at least 50 grams/day. My wife and I were already pretty good about making most of our meals from scratch, so we tended to avoid refined carbohydrates and pure fats.

    I’ve seen weight loss like I haven’t seen since I was in my 20’s. I’m 60 years old. I didn’t start terribly obese – I was about 204 lbs with a 35.6″ stomach circumference (height is 5’11”). Today I’m 192 lbs with a 34.4″ stomach circumference – a loss of 12 lbs and about an inch off my stomach. My abs are starting to show and I’ll be one of the fittest men at the pool this summer.

    I should note that I’m also working out regularly. 11 weeks ago my wife and I committed to a program that has me lifting weights 4 days a week (lower body on the 1st & 3rd days, upper body on the 2nd & 4th) and doing a Tabata HIIT workout on a recumbent exercise bike once/week. I track my calories/nutrition using the free MyFitnessPal app and give myself extra calories to consume based on the exercise I perform that day. We also tend to go on 2-4 mile walks and 20-mile bike rides when we can fit it into the schedule/weather – those are the days when I usually “earn” a beer or other splurge.

    I know I’m an anecdote, but I believe the basic advice from this article is what has worked for me. Why am I confident this advice made the difference? I started my recent weight-loss journey in March 2020, when I retired from work. At that time I weighed 216 lbs and my stomach was about 37″. It took me 22 months to lose the first 12 lbs – the same amount of weight I lost over the past 15 weeks. Over those 22 months I was trying to lose weight, making healthy home-cooked meals, tracking calories with the app and doing the walking/biking (and some off&on weight-lifting).

    But what about all the weight-lifting, etc. I started 11 weeks ago? Well, I looked back at my records and the 4 weeks prior to all that exercising: I lost 3 lbs and 0.3″ over those 4 weeks (down to 201 lbs & 35.3″). That’s the same average pace of loss for the entire 15 weeks. To me the only explanation is that the diet advice is the main influence. I like the strength and fitness I get from the exercising, but the diet guidelines are what drove the weight loss.

    So, thanks Dr. Rushworth – for researching and writing this article.

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