Study: It’s All About The Calories

By Mike Howard

If you’ve taken your dieting advice from pop diet book authors in recent years, you’d think that calories are not important or at least of secondary importance when it comes to battling the bulge. The largest dietary trial of its kind – published in the New England Journal of Medicine shows that calories matter – no matter how you split them. More than 800 overweight adults in were assigned to one of four diets that reduced calories through different combinations of fat, carbohydrates and protein. Each plan cut about 750 calories from a participant’s normal diet, but no one ate fewer than 1,200 calories a day.

While the diets were not named, the eating plans were all loosely based on the principles of popular diets like Atkins, which emphasizes low carbohydrates; Dean Ornish, which is low-fat; or the Mediterranean diet, with less animal protein. All participants also received group or individual counselling. The breakdown of calories was as follows:

Group I: 20% Fat, 15% Protein and 65% Carbohydrate
Group II: 20% Fat, 25% Protein and 55% Carbohydrate
Group III: 40% Fat, 15% Protein and 45% Carbohydrate
Group IV: 40% Fat, 25% Protein and 35% Carbohydrate

Here are the findings

  • After two years, every diet group had lost — and regained — about the same amount of weight regardless of what diet had been assigned.
  • Participants lost an average of 13 pounds at six months and had maintained about 9 pounds of weight loss and a two inch reduction in waist size after two years.
  • While the average weight loss was modest, about 15 percent of dieters lost more than 10 percent of their weight by the end of the study.
  • After about a year many returned to at least some of their usual eating habits.
  • While health markers for cardiovascular disease and diabetes were similar, the highest carb group did not reduce fasting serum insulin levels
  • All diets decreased triglycerides and blood pressure fairly evenly
  • The lower fat diet reduced LDL cholesterol moreso than the high fat diet, while the highest fat, lowest carb diet raised HDL cholesterol moreso than the high carb, low fat diet.

While attendance at counselling sessions were linked with better weight loss, this was not true for every dieter.

According to lead researcher Dr. Frank Sacks:

The effect of any particular diet group is minuscule, but the effect of individual behavior is humongous. We had some people losing 50 pounds and some people gaining five pounds. That’s what we don’t have a clue about. I think in the future, researchers should focus less on the actual diet but on finding what is really the biggest governor of success in these individuals.


As the researchers pointed out, behavior seems to be central. Almost all long term studies on diet and weight loss seem to follow the same pattern regardless of the dietary intervention; a somewhat rapid weight loss in the first 6 months followed by a regain.

On a positive note, most people of this age group tend to gain on average 4-5 pounds in the same time frame of this study. Therefore, a 9 lb loss and a couple of inches over this span can definitely provide a health boost.

It seems we have to figure out how to make long term habit changes to steadily and significantly change health for the better.


  1. Ed

    One more comment since diet blogs feature many readers with very strongly held opinions – many people here post very strongly held opinions about their preferred “proper diet”. I agree with the comments of Henry and Jody above. One size does not fit all and we should be cautious about claiming that what works in our little world necessarily works for other people. That I have several allergist confirmed food allergies is a hint that my body processes food differently that many other people’s bodies. The diet that is “best” is what ever method works for the individual. (I like “low GI” myself.) Much of what we were taught about nutrition over the years has also subsequently been proven wrong and we need to be skeptical.

  2. Ed

    Dr. Michael Eades has a different take on this study posted on his blog. He notes that the “low carb” diet was 150 grams of carbs per day, which is quite a bit higher than what low carb eaters consider low carb. The dietary test gave everyone low calorie intake, and when this is done, the low calorie effects likely swamp the effects that any of the specific diets might otherwise have on their own. The study, he says, appears to have first determined the desired outcome and then designed a test to yield that outcome.

  3. Jody - Fit at 51

    Henry, not sure if you thought I was saying low carb was a quick fix. I am talking about the crazy grapefruit diets, cookie diets, restriction of whole food groups and more. As I have said before, I have found what works for me & I eat pretty clean 85-90% of the time with a close to 40-40-30 breakdown of whole grains, veggies, lean protein,healthy fats & nuts. It may not work best for another. As mentioned above, everyone needs to find out what works best for them but they have to be able to sustain it long term.

  4. Henry

    While I would agree that one has to find a diet that works for them, I would not agree that a low carb diet is a quick fix. Neither is a high carb diet. There are millions of vegetarians doing just fine, as well as low carb enthusiasts that enjoy a low carb lifestyle. In fact, low carb can work just well for many individuals that are pre diabetic and diabetic.

  5. skinny attitude

    Jody speaks the truth 🙂
    I never believed these “high/low” diets to be healty, you need a balanced diet. There would be no market for these diets if people would realize that loosing weight is not a one time quick fix.

  6. Jody - Fit at 51

    DaleK, so true, the rocket science part is how to keep people motivated to lose weight & make long term, sustainable & attainable changes in their life. I also agree with you that what works for you may not work for me & what works for me may not work for another. We all have to find the balance that woks for us & allows us to live happy, healthy & fulfilling lives. We need to find that balance that provides long term success.

    Like Erin says too & I always say to people as well, it comes down to lifestyles changes & not quick fixes but changes that you KNOW you can live with long term!

  7. PRHL

    I totally agree with your recommendation (eat slowly) and with its reason, i.e. that the body needs a few minutes to know that it is full.
    And I may add: Most people eat at least three times a day, and unevitably they eat comparable meals.
    Therfore after a while they must know what food they need to become full.
    If you eat too much, you also feel that after a few minutes. So: When you have eaten – say – five times comparable meals, and every time you felt overeaten, you must know that this portion is simply too much.

    I hope you get the picture…

  8. Erin

    I firmly believe that the “cleaner” you eat, the “leaner” you will be. I have been in the fitness business for over 15 years and have worked with many clients who have experimented on many different diets. The clients who lost the most weight and kept it off made lifestyle changes, and didn’t follow a strict diet. I watched how they transformed from doing hard work and saying no to large portions and a lot of processed foods. In fact, I had many of my clients only give up diet sodas and not change anything else in their diets and they lost weight. This proves that the chemicals in processed foods, especially in diet sodas have to go somewhere. Just because a food has 0 calories, doesn’t mean it just evaporates from our bodies. We have to figure out where it goes, what nutrients we need from it, and how to digest it. This goes to show that it must go somewhere as these clients proved my point. In fact, I was watching The Biggest Loser last week and the first diet quiz question was, “What makes you live longer, diet sodas, or regular sodas?” And, the answer was regular soda of course and they both got it right. I was surprised, but happy that the trend is eating right, not trying diet after diet!

  9. DaleK

    In the end it’s always about calorie deficit over time. Period. How many studies do we need to prove this? I wish they’d spend the money on research that would actually help someone.

    Some of us have a hard time staying in a deficit when the marco ratios aren’t optimal for our individual metabolism. I require fewer carbs in order to consistently remain in a deficit. Too many and I get hungry. And eat. Sometimes more than I need.

    To quote the author, “The effect of any particular diet group is minuscule, but the effect of individual behavior is humongous.”

    We are what we eat. Every food we put into our bodies have hormonal effects which can influence eating behavior. If I eat too many carbs, processed or not, it becomes hard to moderate my calorie intake.

    What’s right for me will be detrimental to another. What works for me today may not work so well next month. My last two carb refeeds were followed by a day of ravenous hunger – and I’m not talking about the usual carb cravings. I’m talking intense physical hunger. This hasn’t been the case in the past.

    So, while in the end weight loss is simple – calories in vs calories out – how we go about getting people to stick to a deficit over time is the rocket science part of weight loss.

  10. Spectra

    Carbs are stored as glycogen in your muscles/liver and glycogen holds onto water very well. When you cut way down on carbs, you lose the glycogen and its associated water and you lose weight. That’s often why a lot of people report such great success with Atkins…it does make you shed a lot of water weight VERY quickly.

    I’m not a huge no-carb person, but I do try to avoid processed foods, most of which are nothing but refined carbs and fats with flavoring added. Those types of food are very easy to overeat…if you grab two handfuls of chips instead of one because you’re hungry, you get 200+ more calories than you meant to grab. If you grab two handfuls of carrots instead of one, you eat an extra 40 calories or so. The amount of damage done by picking your snacks wisely is pretty obvious.

    A lot of why people lose weight on Atkins is because they’re sort of being forced to not eat processed foods…they can’t eat breads, chips, cookies, cakes, soda, etc. Well duh, if you can’t eat those things, you’re eliminating those calories from your diet. Even if you replace them with healthy things like turkey breast, broccoli, celery sticks, etc., you’d have to eat a whole lot of those foods to overeat and gain weight.

  11. julie

    I eat high produce diet. I still eat a Girl Scout cookie, a burger, a slice of bacon, pizza on occasion. I eat higher calories than most who are “dieting”, and I lose weight. (I’m not sure about this point, because most people under-report calories by a LOT. Plus, I don’t count calories, as it would be too difficult, in that I process most of it myself). Fiber interferes with digestion, fat and protein let me feel content and make me stop eating. Carbs make me happy. So I’m happy, eating my fruits and veggies and beans and some whole grains (not a fan, but I try) and a bit of meat, a bit of junk, and I’ve lost 30 pounds in the last 6 months or so. No complaints from me.

  12. Spectra

    I’m with you, Heather. I found that once I eliminated processed foods, I had a much easier time losing and maintaining my weight. Not that there’s anything horrible in processed foods that makes it impossible to lose weight while eating them, just that I think unprocessed foods tend to have more fiber and a higher water content, making it harder to overeat them from a caloric point of view.

    I like to think that our ancestors probably ate all the wild fruits and vegetables and nuts and whatnot without worrying too much about eating too many of them. So I try to do the same and it definitely works for me.

  13. Jody - Fit at 51

    I agree & I do think people can figure out when they are full if they slow down when they eat. Take a bite, set the fork down, chew completely & swallow and then continue. It takes the body 20 minutes to register that it is full so one does have to slow down the eating process and just enjoy it. I used to not “know when I was full” but this really works & like everything else, it takes time to understand your body & what it is telling you.

    For Bob, I am glad you have found what works for you but I do think many people eat way too fast & that is a big problem for many of them.

  14. bob

    Unfortunately for many, including me, I could never find the point of being full on a high carb, low fat diet, until I was overstuffed and had ingested too many calories. Too say when you eat until you are full did not work for me on most diets. When I switched to a low carb diet, not worrying about fat or what type of fat I was eating, I was able to get full without overeating. That is the beauty of Atkins. I can now eat 2000 calories on a low carb diet and feel full. Another benefit is that my numbers are excellent, never been better. One can call Atkins extreme, but it works for me…and millions of others. It’s too bad this study did not include the real Atkins deal.

  15. PRHL

    It’s amazing how long ideologies like “Atkins” could have any followers, and that it probably will continue to have followers even after this study.
    But to be fair, Atkins sometimes said something right, e.g.:
    “If you are full, stop eating!”
    Now that is the key: Do not eat more than your body needs. And this advice goes for other diets as well.
    Personally, I recommend to eat virtually every kind of healthy stuff: bread, fruit, vegetables etc., and to stop eating when you are full.

  16. Jody - Fit at 51

    Processed foods tend to have more fat, calories, sugar and more so I can see how it is harder to lose weight eating processed foods… it is easier to overeat these good tasting foods. Also, when you eat more natural foods, whole grains, veggies, nuts (& healthy fats), good protein, your body works better & things “move through you” better.

    Also, although I believe in calorie in, calorie out, I also have found from my own experience that my body reacts better to a certain set of food & certain ratios of protein, carbs & fats. I have had to change things over time with hormones & age & I just pay attention to that. Like said above, different ways of eating work better for certain people & I think a lot of this comes down to just what that particular person can handle for life & stick with for life along with finding out what works best for you.

    As the article stated, “The effect of any particular diet group is minuscule, but the effect of individual behavior is humongous. I think in the future, researchers should focus less on the actual diet but on finding what is really the biggest governor of success in these individuals.”

    People have to take accountability with their health. Eat less if they are eating too much, exercise, eat better etc. Like I have said before & this blog makes note of often, people have to figure out how to make long term habit changes to steadily and significantly change health for the better. It is in their hands.

  17. Amber

    From the actual article: ‘There is intense debate about what types of diet are most effective for treating overweight — those that emphasize protein, those that emphasize carbohydrates, or those that emphasize fat.’

    These diets did high protein and high(ish) carb. There was no high fat/low carb.
    This study said that it was supposed to be making up for the small study sizes and short duration of previous studies. Though it did that it did not test all types of food combinations as it suggested that it would be doing. In the design section it said ‘We designed a randomized clinical trial to compare the effects on body weight of energy-reduced diets that differed in their targets for intake of macronutrients — low or high in fat, average or high in protein, or low or high in carbohydrates ‘
    It did not do this.

    The carbohydrates were also varied in the two sets, so that you had more than one factor changing between groups – how do you know what was going on with that group if you changed two factors?

    As a piece of work it did not seem to do what it suggested it was going to do.

  18. Vivian

    Heather, this short article in the Economist that touches on how cooked foods are more easily digested and how (and why) the body absorbs more of their calories would seem to support your personal experience.

    Like you, I’ve experiencedthe same.

  19. Pahood

    Not complaining, just pointing out. I’m happy.

  20. Ben

    The study apparently didn’t have the goal to measure “extreme” diets. I’m not sure what makes that a problem. They just weren’t looking for the answers to the questions you’re interested in. Instead of complaining about this one, why not go look for the study of the extreme diets?

  21. Pahood

    We can listen to the Queen of England if we want, however the study did not include a high carb or low carb diet, such as Atkins or Ornish. That is the problem with this study.

  22. Amber

    My point is that it says before the breakdown they were based loosely on Atkins, Ornish and the med diet. Non of those diets were Atkins based. The carb level was way too hight.

  23. Heather

    After years and years of Calorie counting (and with a very high physical activity level) and nothing.

  24. Heather

    I’m merely saying my own personal experience. I am losing weight on more Calories than I ate previously. Period. I’ve lost 16 lb and 9% body fat so far in 2009.

  25. Regina Wilshire

    Maybe not…I did a two week self-experiment to specifically keep carbohydrate at or below 40g (net) a day, consume adequate protein and include enough fat calories to exceed my requirements each day. Not only was it really hard to overconsume calories with this macronutrient framework, I lost 4.5 pounds in the two weeks eating enough calories where I should have gained about two pounds with the 6575-calorie excess over the period.

  26. Booyeah

    I eat so-called processed foods when I diet and I have no trouble losing fat. I just make sure I stay within my calorie and macronutrient goals for the day.

    Do you honestly think there’s some secret boogie man in processed foods that is keeping you from losing weight?

    Processed foods tend to be calorically dense, and they usually taste really good so people tend to over-eat them.

  27. Booyeah

    What’s your point? Eat a zero carb diet with more calories than your body requires and you will get fat. Period.

  28. Booyeah

    Lyle McDonald has been saying this for years. He’s the only “guru” I listen to anymore because he’s the only one not out to get rich and who bases his work on actual scientific studies.

  29. Amber

    Non of these diets is low carb ie Atkins. Even at 35% calories and 1200 calories thats just over 100g of carbs. That is not low carb at all. Thoes carb levels are high enough that any benifits seen normally with low carb eating would not be seen

  30. Heather

    I do have a couple things with this study. Not things that can be avoided.

    Primarily, there was nothing to ensure adherence. So perhaps one works better if followed but is harder for a person to follow– overall results turn out the same.

    I also believe that different ways of eating might work better for different people, if just due to psychological components, maybe more. Not being able to choose your diet takes that away.

    Also, there’s none that focuses on avoiding processed foods.
    My main thing is after a long, long time thinking a Calorie is a Calorie and trying to lose weight and spending my time light headed and not losing weight- I eliminated processed foods from my diet and have been losing weight super fast even though I’m eating significantly more Calories a day than I was before. A personal anecdote is not science, but there you have it!