From the research journal Duh: To lose weight, eat less

Researchers have determined that the key to losing weight is to consume fewer calories.

Okay, it's actually more interesting than the summary suggests. The researchers compared a variety of different popular diets and found that it didn't matter what diet you were on; the weight loss (and regain) was the same. The controlling factor was how many calories you consumed.

Comments (28)
  1. Joshua Ganes says:

    The other key is increase activity (exercise). Weight control is simple math: (calories in) – (calories out). The challenge is self control to balance the chequebook.

  2. Tony Mach says:

    Yeah, calories in = calorie out. Right. Right?

    "That experimental binge should have translated into a weight gain of roughly 24 pounds (based on 3,500 calories to a pound). But some gained less than 10 pounds, while others gained as much as 29 pounds."

  3. Skuggi says:

    I think the point of different diets is to make it easier to reduce your calorie intake. I'm sure some diets are easier to maintain with the same reduction in calorie intake.

  4. No One says:

    @Tony Mach:

    1. The website is named "Perfect Health Diet" and is selling a book.  Not sure it'll be entirely unbiased there.
    2. Yes, calories in – calories out is a simplification of the truth but it's fairly accurate simplification.  Base metabolic rate and muscle efficiency affect the calculations for "calories out" and efficiency at extracting calories from your food (which is affected both by personal physiology/genetics and structure of the food you are digesting) affects (mostly) "calories in" (and to a lesser extent "calories out").  But that still simplifies down to the calories in – calories out equation without much loss.

    Unless they give the distribution for the discrepancy in weight gain from their experiment it's not an experiment — it's an anecdote.  Most likely something like 80% of the subjects in that "experiment" were within 20% of 24 pounds gained.

  5. Tim says:

    Tony, yes, that holds true. What is really being found out is that some people have a higher calories out response to more calories in. You can't change the fundamental mathematics behind calories in/out, though.

  6. Mike says:

    In other exciting news: Spend less than you make to save money!

  7. Somebody says:

    From the article:

    "After two years, every diet group had lost — and regained — about the same amount of weight regardless of what diet had been assigned."

    "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 five 5 pounds. That's what we don't have a clue about."

    So the biggest result of the study, that is avoided by the article, is that dieting does not work in the long run.  You're fighting your body's natural metabolism when you diet.  And nature always eventually wins out in the end.

  8. Brad says:

    I am surprised and disappointed by this study.  To start, the 4 diets were too similar – nothing was close to the "Atkins" diet, and all had less protein than the zone diet.  There was probably too much variation between too few patients, and the graphs were convoluted, but "low-fat, high-protein" looks like it did much better than both "average-protein" diets on the graphs.


    Very small variations in diet do not produce statistically significant results in relatively small sample sizes.

  9. Falcon says:

    Duke Nukem Forever displays random tips during (notoriously long) loading screens. The list includes some joke tips, such as:

    • "Take less damage to avoid being killed"

    • "When being shot at, try to avoid bullets"

  10. alegr1 says:


    The trick is not just give up sugar soda, it's also to give up sugar-free (artificially sweetened) soda. It screws up your pancrea, too.

  11. James Schend says:

    @Falcon: the (perhaps apocryphal?) instructions to the first Pong game where: "avoid missing ball for high score".

    Some early shooters had their instructions given as: "shoot everything, don't get hit"

  12. Kzinti says:

    Sugar-free soda is actually worst then sugar soda for your waistline. The main problem is that your body believes / reacts as if it is receiving sugar (but isn't). The result is your get more hungry / crave sugar.

  13. Marc says:

    One problem with the simplistic (calories in) – (calories out) view is that your body burns more calories when you eat more, and it burns fewer when you eat fewer, without changing activity levels. Another problem is that the way we measure calories is not quite the same as how the body uses them. A third problem is that different calorie sources may have different effects on satiation. When I eat moderate to high carb diets I often feel hungry again very quickly, but a lower carb, higher fat diet keeps me feeling full and I end up eating less. Likewise, different calorie sources have different effects on metabolism.  

  14. Tim says:


    While you may be correct about how your body may react (craving sugar), your statement about it being worse for your waistline is false. In fact, many people I know, myself included, lost weight by merely switching from regular to diet soda. However, different people react different ways to the same input.


    None of what you said is a problem with the formula, but with how people try to apply it. Your first claim merely says that the calories out can be modified by calories in. Can you rephrase your second so that it isn't merely an assertion, but one backed by a citation? The third thing you mention is not at all a problem of the formula. However, it certainly can make modulating the "calories in" side easier if you know foods that will satiate you longer. Ultimately, though, the formula is true: if you take in more calories than you expend, you will gain weight. If you expend more calories than you take in, you will lose weight. If you are about equal, you'll maintain weight. Nothing is wrong with that view or understanding.

  15. Dave says:

    There's also a simple bit of physical exercise that you can do to help you lose weight.  It involves moving your head to the left, then to the right, then to the left again, and then back to the right whenever someone offers you rich/greasy/sugary food.

  16. Dave says:


    The trick is not just give up sugar soda, it's also to give up sugar-free (artificially sweetened) soda.

    It screws up your pancrea, too.

    Given that you're calling it "soda" I'm guessing that you're in the US: An easier trick is to switch from high-fructose corn syrup "sugar" to real (cane) sugar.  You still get the sugariness, but it's much easier to lose weight on it (or not gain so much weight).

  17. Ranma says:

    When I gave up sugar soda, I dropped almost 1200 calories a day, I figured easy weight loss. My Doctor came in and told me, "Well, as far as I can figure it, your body decided you were fasting, and your metabolism slowed down…" I gained 10 lbs… *tears* My other diet choices hadn't changed, we kept a diary to make sure of that. So now we're hitting the gym, since apparently dieting alone is just not enough…

  18. Cameron says:

    @Somebody – Yes, all diets fail in the end… IF you do not keep dieting. Overweight and obese people MUST change their lifestyle, they cannot just go on a calorie restriction diet, lose weight, and then go back to "normal". There is no normal left. You can think of it like recovery for addicts, because it kind of is.

  19. Alex says:

    Apart from medical reasons, diets don't make sense. Find out what your body actually needs to function properly, eat accordingly and move your ass. Aka: become actually fit.

  20. Marc says:

    @Tim – Note I was not denying the laws of thermodynamics, merely their overly simplistic application to nutrition. Real biological systems are more complex, which makes the formula nearly impossible to apply for nutrition, at least if you want to use it to predict weight loss with any accuracy.

    As for measuring calories, this link has some information ( Note the old way would burn the food and measure the energy released, but last time I checked, the stomach is not a furnace. The Atwater System is a ultimately a guess, though a much better guess based on better data and assumptions. Wikipedia has some more information and highlights some of the problems (…/Atwater_system). That should get you started should you want to research it more deeply.

  21. Sam says:

    Tom Naughton has a great analysis of this study, which you absolutely should read:…/another-bad-study-badly-reported

  22. Killer{R} says:

    Just another proof of law of conservation of energy and matter.

  23. GWO says:

    @Sam Ahh, "Fathead", the "Loose Change" of the diet industry.  Of course, Tom Naughton's single anecdotal data point outweighs every single study ever done.

  24. Jeff says:

    I am blown away that a simple fact like this has caused so much controversy.

  25. davep says:

    Dave 9 Jan 2012 5:13 PM # "Given that you're calling it "soda" I'm guessing that you're in the US: An easier trick is to switch from high-fructose corn syrup "sugar" to real (cane) sugar.  You still get the sugariness, but it's much easier to lose weight on it (or not gain so much weight)."


    The so-called "high fructose" corn syrup used in drinks is 55% fructose. Sucrose ("real" sugar) is 50% fructose (sucrose is a binary sugar but is split into its components early in digestion. Also, fructose is sweeter than sucrose, which means you don't need as much of it.

    There really is no dietary/nutritional reason to consume anything but small quantities of sugary drinks including fruit juice (for people who not very active)

  26. Gabe says:

    I don't understand all this concern over calories. Why not just measure weight? It's trivially easy to tell how much food weighs, so as long as food is labeled with how much of it will be excreted as waste, we can assume the rest will become part of our bodies. Then we just have to figure out how much we will exhale as carbon dioxide and how much will evaporate based on our activities in order to figure out the net weight gain/loss. Right?

  27. Jolyon Smith says:

    It's not actually that simple at all.

    Yes more calories in than out = weight gain, but the real "controlling factor" increasingly appears to be PROTEIN.

    Our bodies need a certain amount of protein… if you each protein rich foods then you need to eat less to satisfy that need.  If your diet is low in protein then you need to eat more in order to consume the required amount of protein.  Thus you end up eating more calories… but you can't simply decide to eat less to reduce your calorie intake because your body will be craving the protein that it needs.

  28. GWO says:

    @Jolyon Smith: That's a hell of a verbose way of saying "You still need to eat a balanced diet"

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