Diets Do Work?

Does eating fewer calories help people keep extra weight off? Or does it just make people feel deprived, leading to a "boomerang" effect of more binge eating and weight gain down the road? A new study published in the American Journal of Health Promotion has examined these questions and found that cutting calories may actually be a good way for middle-aged women to keep the extra pounds at bay.


The study followed 192 women for three years. The women had an average age of 40 and had not yet reached menopause; they also did not smoke and were not obese.

At the beginning and at the end of the study, the women underwent detailed physical exams, during which their weight and body fat were measured. They also spent a week at each end of the study weighing and recording every bite of food they ate.

At the end of three years, the researchers found that the women who had made an effort to cut back on their eating were 69% less likely to have gained much weight (more than 2.2 pounds), even if they did not exercise more than anyone else. On the other hand, women who did not practice restraint in their eating were more than twice as likely as the others to have gained at least 6.6 pounds.

The study also found that women who, over the course of the study, increased their “emotional eating” — or eating to cope with emotional states such as depression, anxiety, or boredom — gained more weight during that time.

The researchers concluded that women should “increase their dietary restraint over time or they will likely gain weight” and that they should “learn to control their food consumption during emotionally challenging situations.” The researchers recommended that people cut calories by recording what and how much they eat, putting less food on their plates, and increasing their consumption of vegetables and fruits.

You can read a press release about the study here and WebMD’s coverage of the story with some more statistics here.

Earlier this week, David Spero wrote about the importance of exercise, rather than diet, in keeping weight off once you’ve lost it (read more in his blog entry “Diets Don’t Work?”). Which do you think is more important? Have you tried to restrict calories as you’ve gotten older, and if so, have you had much success? Share your thoughts with a comment!

Learn more about the health and medical experts who who provide you with the cutting-edge resources, tools, news, and more on Diabetes Self-Management.
About Our Experts >>

  • CalgaryDiabetic

    Dear Tara.

    The study has confirmed the first law of thermodynamics as it applies to food: Energy input- energy output= Fat accumulation.

    Also it has confirmed that your output decreases as you grow older.

    No problem with the two findings.

    Yes, I have tried last year to write down EVERY thing I put in my mouth and the amount of extra calories burnt at the gym or walking. Lost 10 lb over 60 days, I thought that a slow instead of a radical diet and the body would not notice.

    Well not so, after 11 pounds all hell broke loose and not only did I gain back the 10 lb but another 10 lb so I am worst off.

    Does exercise only do? No since you can eat in 5 minutes 600 calories what it would take me 1 hour to burn off at the gym. That is a 12 to 1 ratio in favour of eating.

    Fruits and veggies like Motherhood and apple pie (would not think of eating any of that). Well when you are on insulin these need extra insulin=extra hunger= extra weight gain=extra insulin and so forth.

    Don’t know the answer obviously if we had some thing to curb the appetite. Inactivating the olfactory nerves? Or nuking the taste buds? The person that discovers this will be a multi-billionaire.

    If you are on insulin I am starting to believe that a low carb diet helps control the appetite somewhat. Will this be enough to loose significant weight remains to be seen.

  • Nicky

    I think that for diabetics – particularly Type 2s – the key is to keep insulin, and blood glucose levels, as low and as steady, as possible. The implications of this is likely to be a lower carb lifestyle – so plenty of green veg, not a lot of fruit. This means that you’re not going to get those dreadful carb hunger binges as your blood glucose swings up then crashes, which makes reducing calories possible, if required. The other way to reduce insulin resistance is, of course, to exercise – but if you’re doing it for blood glucose control, a 30-min walk after your meal may be more useful than, say, a run which your body interprets as stress, and responds to by raising your blood glucose levels.

    What a fun disease we have ūüėõ

  • David Spero RN

    I like the article and both comments so far. There is a LOT to be said for eating green vegetables – they keep you full and not feeling as deprived. They provide vitamins and slow absorption of carbs into the system.

    I also like what Nicky said about walking sometimes being better than running, because it doesn’t stress you. Stress is the big thing missing from the study. It’s not as simple as “Energy input- energy output= Fat accumulation.” Stress will cause your body to deposit abdominal fat much more quickly.

    Low carbs seems to work for an awful lot of people, but not for everyone.

    I think exercise is best spread throughout the day – the term “active lifestyle” is a good way to think about it. Be more active. IMHO, that’s why older people tend to get T2D. They’re not moving as much.

  • CalgaryDiabetic

    Dear David.

    The equation represents the ideal case that diets are based on. As you pointed out reality is different.

    The equation presupposes that fat is the only storage device in the body. Unfortunately this is no so, perversely the body can eat muscle mass instead of consumming fat when you diet. And reducing muscle mass will make any additional weight loss very difficult or near impossible.

    Also since diets are stressful, stress produces cortisol and cortisol adds to tummy grease. You wonder if the most horrible situation can happen that you add or maintain fat on the body and loose muscle mass. This can be counter-acted a bit by exercise.

    This may be so I remember looking at pictures of people being starved to death and the muscles looked to be totally gone yet there still was some tummy fat.