Why hasn't there been a difinitive study on which foods cause weight gain the most?

The topic of diet is so universal, with several articles written every month in every women’s magazine, and probably the largest section of the health and self-help sections of every bookstore.

So why hasn’t someone just done the key tests?
I’m thinking a lot of the existing “clinical” tests rely too much on subjective recording of food eaten and exercise done.

But surely there must be large groups in hospitals and institutions (from hospitals to old folks homes to prisons) where very accurate studies could be done.
Just offer a few hundred inmates their choice of low-fat, low-carb, or whatever diet, and see whether they gain or lose weight.

Surely this has been tried. So why don’t we have answers?

Any medical institution is under a legal and moral obligation to provide the necessary nutrition. In any case, using the elderly or the ill as a test basis is flawed from the start - you need to test healthy people leading a normal life for the results to mean anything.

And in any case, if you read articles in medical and scientific journals, rather than Cosmo, you’ll find there already exists a general consensus through scientific study of what constitutes a healthy diet.

That has been done all the time. People are put on diets all the time and the results are measured. People are overfed and the results are measured too. They are given different types of diets, etc.

At bottom, calories count. That’s not to say that there aren’t other factors, but nothing can override that basic fact.

A lot of tests and research projects have been completed already to determine which foods are more calorically dense and which have the most unhealthy or healthy fats per serving. Also, scientists have tested the nutritional value of most foods and have determined which foods are nutritionally void and which aren’t. Plus, there have also been many tests on which foods people overeat the most, and in what situations people tend to overeat these foods. I think it’d be safe to say that scientists are aware of which foods tend to cause weight gain.

GorillaMan - Ok. Since you have the answer, tell us.
What’s the best food to lose weight?
I’m talking single variable here, not the broad advice “do all these many things, give up drinking, exercise more, get a less-stressful job…”
In other words, what are the results of such a test as in the OP (using the scientific method = changing only one variable at a time, diet only, not lifestyle).

Some people claim they lost weight by cutting carbs. Did they?
Some people claim they lost weight by cutting fat. Did they?

Some say the particular diet doesn’t matter, but just total calories (and that also presumes that people can adhere to an identical calorie total no matter which food they eat). Is that true?

Here is an example

http://cardiology.jwatch.org/cgi/content/full/2003/808/1

I don’t know which ‘food’ is best for losing weight in the sense that no one food is good to live off of. There are tons of studies on the subject of various dieting methods though and I recently read a study that a diet of around 35% fat was better than a low fat diet of 20% fat because the 35% fat diet allowed more variety so people stayed on it.

Mean weight loss by 6 months (the primary endpoint) was significantly greater in the low-carb group (–5.7 kg) than in the low-fat group (–1.8 kg), with a similar difference when dropouts’ baseline weights were not used.

So its not just how much weight you lose, its how liveable the diet is.

Here is a study on dairy and weight loss

http://content.health.msn.com/content/article/85/98720.htm?printing=true

In the study, researchers compared the effects of three different calorie-restricted diets on weight loss in 32 obese adults. Each of the participants reduced their daily calorie intake by about 500 calories per day for 24 weeks and were divided into three groups:

High-dairy. Total calcium intake of 1,200-1,300 milligrams per day from three to four servings of dairy foods, specifically milk, hard cheese, and yogurt.

High-calcium supplemented/low-dairy. Total calcium intake of 1,200-1,300 milligrams per day made up of no more than one serving of dairy per day plus an 800-milligram calcium supplement.

Low-calcium/low-dairy. Total calcium intake of 400-500 milligrams per day with no more than one serving of dairy per day and a placebo supplement.

The study showed that all of the groups lost weight, but those who ate the dairy-rich diet lost the most with an average of 24 pounds compared with 19 pounds in the calcium supplement group and 15 pounds in the low-calcium/low-dairy group.

Well, if losing weight is all you care about, then stop eating.

Yes, that’s a ludicrous suggestion. Losing weight healthily is the important factor. A varied diet, incorporating a full range of nutrients, and within recommended calorific intake, coupled with regular exercise, will maintain a healthy body. There’s no one food that will help by itself. If you need to lose large amount of weight, consult a dietician - they’re trained to answer the questions you ask. And they’ll be able to explain the problems associated with restrictive diets (including Atkins), due to their failure to introduce variety or regularity into everyday eating behaviours.

There ain’t no such beast. See below.

Yes.

Yes.

It’s not quite so simple. Like I said earlier, calories do count. However, there are other factors that come into play. Different types of carbohydates, proteins, and fats have different effects on the body. Nutrient timing matters–sucking down a high-sugar drink right before bed is pretty deleterious, but doing it right after your workout is a pretty good idea. And then there’s the matter of biochemical individuality–what works for one person won’t necessarily work for another.

Let’s be a little clearer here. There are two types of weight–fat and lean mass–and it’s good to differentiate between them. Losing lean mass but not fat means you weigh less, but you’re fatter than before. It’s a pretty complex topic, but to maintain an ideal ratio of fat to lean body mass, the best general principle is to eat a moderate amount of calories, eat every 3-4 hours, and concentrate on slow-digesting foods that are rich in micronutrients (vitamins, minerals, phytochemicals, etc.).

Assumed, your question is based on a false premise: that there are certain foods that cause people to gain or lose weight. There isn’t any such food. As ultrafilter said, calories are what count, and it doesn’t matter what food they come from.

Body weight is:

Input (calories in the food you eat)
vs.
Output (calories expended in maintaining your body and in exercise you do)

If Input exceeds Output, you will gain weight.
To lose weight, Output must exceed Input.

This is the basics of any diet, and it’s not that hard to understand.

But nobody likes it, because it means that to lose weight, you will have to:

  • get yer fat ass off the couch and do some exercise.
  • stop stuffing yer face with ice cream & candy & potato chips, etc.
  • or both.
    That’s hard & unpleasant to do, so everybody is searching for some magic diet that will do this painlessly. (And a whole industry has grown up of people who will make money by selling you some form of “magic diet”, of books about it, or “painless” exercise machines, etc.)

But it all comes down to a simple fact of life: To lose weight; eat less, or exercise more.

For a fast healthy diet- that you won’t stay on- try Atkins. It works. But you won’t stay on it. Of course- dudes rarely stay on any diet, so… If you are lucky, after losing down to your target weight with Atkins, you can then cut a few "problem foods " out of your diet all together (Chips are a good start, along with fries, and also sugar soda). If you do so, you may well keep about half the wieght off. Increase excersise, and you may keep it all off.

Really- they have done the study the Op asks for- and each food is clearly labeled with the results- they are called “calories”. Pretty much (unless you’re talking some very high fiber and low calorie foods like celery) a calorie is a calorie, and as far as WEIGHT goes, it makes little or no difference.

Atkins seems to work mainly by limiting calorie intake. You cut out 90% of snack foods, and just about every “empty calorie” food (sugar). The protien & fat make you not feel hungry at all, even if you are eating less calories than with sugar calories. It’s also dead simple, and you have a good reason not to “cheat”. It has been shown to work as well or better than “low fat” diets, and with the dieters reporting they felt far less 'deprived" during it. But yes- the chances are high you won’t stay on it (or any diet) for more than a year, and six months is average.

t-bonham is then basicly right. But he leaves out one factor- fiber. Increasing your fiber intake will help you lose some weight. Obese dudes are usually constipated to some extent, and the fiber makes you feel “full” to some extent. Thus, high fiber foods are- to a small extent- the “magic” food you’re looking for. I’d make a WAG and say that many obese dudes could drop 10# just by significantly increasing the amount of fiber they eat. Note that isn’t a lot. However, the Atkins allows plenty of lettuce and celery, so if you also increase fiber a lot with these, that will aid that diet also. And, the extra fiber will make your proctologist happy. :eek:

So here is my “magic diet”. Go on Atkins for at least 6 months- and make sure you get PLENTY of fiber. Eat a whole damn head of celery every day if you like (if you can’t- then try a fiber supplement and a LARGE glass of water. No “laxatives”- just fiber supplements- which are laxatives in a sense…). Add a brisk half-hour walk twice a week, and never drive any distance less than half a mile- walk instead. Afterwards, when you can’t take it anymore, cut a few 'empty calorie" foods out of your diet FOREVER. Say to yourself- “I will never eat another Chip.” Keep off sugar soda. Keep up the walks, and keep up the fiber.

Look, it *is * hard to never eat any ‘junk food’ again, and your vow to go to the Gym 4 times a week just means you’ll pay for a Gym membership you’ll never use after the first month. But any of us can cut out a few foods, walk a bit, and get more fiber.

t-bonham and DrDeth talk a lot of sense (although to my mind, Atkins is not a healthy diet).

The main problem is that we have becomse so fixated on “losing weight” that this is seen as the be all and end all. Losing weight is NOT a good thing in itself. It is a symptom - a sign that the body is not getting enough energy to meet its needs.

Obviously, though, if you are overweight, it is a desirable symptom. However, saying “on this diet you lose weight” is not a recommendation. Live on water and cabbage and you will lose weight, but it is not healthy. I am no dietician, but I am not convinced that ketosis is a healthy state for your body to be in either, despite what the Atkins proponents say.

The best answer I’ve heard to the question “What is the best food to lose weight?” is: “Less food.” And don’t get it from the drive-thru…

I am not convinced that ketosis is anything other than hand wavy pseudo-science. I do accept that Atkins works, purely because on a low carb diet people tend to consume less calories in total. Eating less calories, as ultrafilter indicated, is pretty much the be all and end all of dieting.

I’m not sure what you mean by that. Ketosis is a well recognised phenomenon. My girlfriend is diabetic and she was hospitalised for a couple of days last year due to ketosis, brought on, effectively, by dieting. (Not intentionally - she contracted a stomach bug while abroad that meant she couldn’t eat anything - bad news if you’re diabetic.)

That is the main reason I am sceptical about “fat-burning” being a miracle weight-loss solution. There’s another “-osis” that puts me off Atkins, too: halitosis. My uncle is on Atkins and his breath now stinks.

Hmph. Guess I was wasting my time staying up all night in the ER and in the ICU caring for those diabetics in their ketotic comas then.

QtM, MD

I think there have been some studies on this – not on hospital inpatients, but on volunteers. The usual finding is that low-carb diets are more immediately effective than low-fat, but after about six months they are, more or less, equally effective. IIRC, over the long term (a year or so), low-fat diets are more effective. But no diet can cause weight loss if a person isn’t following it, and few people follow a diet for as long as a year, or even six months. Most people will also gain back almost all the weight they lost.

If you mean which specific foods will cause the most weight gain, that’s really more of an issue for checkout-line magazines than medical journals. The foods that cause the most weight gain are those highest in fat and calories. There are no foods that magically cause more weight gain than other foods with similar amounts of calories and fat. Nor are there foods that magically promote weight loss.

For more on low-carb diets see here.

My issue with ketosis is that it not a good explanation of why the Atkins diet works. It was debunked in this BBC Horizon programme. I accept that the BBC is not a reputable science cite, and I am willing to retract my statement if I am wrong.

Ah, that’s very different. You may be correct there.

[Emily Litella]Never mind![/Emily Litella]

I missed that Horizon programme, and I’ve just skimmed through the transcript.

Argh! That’s precisely what I was alluding to earlier!

Yes, you will lose weight because you are forcing your body to adop inefficient, last-ditch methods of finding energy! How can this possibly be considered a good thing? Have we become so blinded by the “weight loss = good” propaganda? Our bodies are meant to burn carbohydrate for energy. It’s easy and efficient - that’s why we do it.

I say that should read “the wrong sorts of food”. You are screwing with your body’s basic operations.

:confused: We’re not meant to be “peeing out calories”, any more than we’re meant to be anally-leaking calorie-free fat substitute :rolleyes: These things are not the signs of a healthy diet.

I see the programme went on to suggest that it is high-protein foods that trigger feelings of fullness, thus meaning that Atkins people eat less. That makes sense. But you don’t need faddish diets and zero carbs to do that.

That’s not what I said. Read it again: