Dieting (Eating Less and Exercising More) Doesn’t Work in the Long Run


  1. It has nothing to do with lack of willpower
  2. What was the long-term effect of dieting
  3. Cognitive dissonance

It is said that exercising and food restriction is necessary for losing weight. However, we rarely meet those who succeeded in dieting using such a method.

Japanese wrestler Bull Nakano (below) has repeatedly dieted and rebounded, but after having knee problems, it was imperative that she lose weight, so she had a gastrectomy to remove part of her stomach.
She said that “cutting the amount of foods and exercising didn’t make her thinner.”

Japanese comedian, Sugi-chan lost seven kilograms with Billy’s Boots Camp diet method, but rebounded to the same weight afterward.

In this article, I would like to introduce how conventional calorie-based diets are ineffective, based on two books: "Escape the Diet Trap" and "Why Do We Get Fat.”
Please note that most of these are quotations.

1.It has nothing to do with lack of willpower

"Ideas about what causes obesity vary. But you'll almost certainly be familiar with the idea that, at the end of the day, the problem is a product of caloric imbalance: specifically, the consumption of calories in excess of those burned through metabolism and activity. No doubt you'll also be familiar with the idea that the solution to your weight problem is simply to redress the balance by eating less and exercising more.

This advice seems to make sense. The trouble is, not only our collective experience but scientific research, too, shows that applying this advice hardly ever brings significant weight loss in the long term.

The usual explanation offered here is that those who fail with conventional tactics lack willpower and self-control. The reality, though, is that calorie-based strategies for slimming not only don't work, but simply can't work, for all but a small minority.

‘Escape the Diet Trap’ explores the reasons why traditional approaches to weight loss are a crashing failure. It reveals how eating less and exercising more causes the body to resist weight loss, and can actually predispose to weight gain over time."
(Jone Briffa, Escape the Diet Trap. London: Fourth Estate, 2013, Pages 1, 19.)

2.What was the long-term effect of dieting

"Limiting the studies to those where individuals were monitored for at least two years after the start of their efforts to lose weight allows us to assess the long-term success of these approaches. Many of us will know what it is to get a short-term win from eating less and exercising more but it's the long game we're interested in here.


Individuals with an average age of 36 and average BMI of 35.0 were prescribed a calorie-reduced diet (individuals ate about 1,000 calories less each day than the amount needed to maintain a stable weight).

low-calorie diet

Some of the individuals added exercise to this dietary restriction in the form of brisk walking for 45 minutes, 4-5 times each week.

The intervention lasted for a year, and weight was assessed another year after the end of the intervention.

Two years after embarking on a long-term (lasting at least a year) restrictive dietary regime, average weight loss was in the order of just 2 kg. Even when regular exercise is added, the weight loss still only averaged about 3 kg (about 6 lbs).

These outcomes look even more paltry when put in the context of the weight of many of the study participants. For someone of average height, a BMI of 35 works out at about 16 stone. I'd say it's unlikely that individuals of this weight would view a loss of a few pounds as a satisfying return on investment in terms of their diet and exercise efforts.

Another potential surprise is just how ineffective exercise was for the purposes of weight loss when employed as an adjunct to dietary restraint. The results from these studies suggest an additional loss of a mere 1 kg in those who were exercising regularly."
(Briffa, Escape the Diet Trap, Pages 20, 22-3.)

 "Prescribing low-calorie diets for obese and overweight patients, according to a 2007 review from Tufts University, leads, at best, to “modest weight losses” that are “transient” – that is, temporary. Typically, nine or ten pounds are lost in the first six months. After a year, much of what was lost has been regained.

the rebound effect

The Tufts review was an analysis of all the relevant diet trials in the medical journals since 1980. The single largest such trial ever done yields the very same answer. The researchers were from Harvard and the Pennington Biomedical Research Center, which is in Baton Rouge, Louisiana, and is the most influential academic obesity-research institute in the United States.

Together they enrolled more than eight hundred overweight and obese subjects and then randomly assigned them to eat one of four diets. These diets were marginally different in nutrient composition (proportions of protein, fat, and carbohydrates), but all were substantially the same in that the subjects were supposed to undereat by 750 calories a day, a significant amount.

The subiecte were also given “intensive behavioral counseling” to keep them on their diets, the kind of professional assistance that few of us ever get when we try to lose weight.

They were even given meal plans every two weeks to help them with the difficult chore of cooking tasty meals that were also sufficiently low in calories.

The subjects began the study, on average, fifty pounds overweight. They lost, on average, only nine pounds. And, once again, just as the Tufts review would have predicted, most of the nine pounds came off in the first six months, and most of the participants were gaining weight back after a year.

No wonder obesity is so rarely cured. Eating less –that is, undereating–simply doesn't work for more than a few months, if that."
(Gary Taubes. Why We Get Fat. New York: Anchor Books, 2011, Page 36-7.)

3.Cognitive dissonance

cognitive dissonance

"This reality, however, hasn't stopped the authorities from recommending the approach, which makes reading such recommendations an exercise in what psychologists call “cognitive dissonance,” the tension that results from trying to hold two incompatible beliefs simultaneously.

Take, for instance, the Handbook of Obesity, a 1998 textbook edited by three of the most prominent authorities in the field–George Bray, Claude Bouchard, and W. P. T. James.

“Dietary therapy remains the cornerstone of treatment and the reduction of energy intake continues to be the basis of successful weight reduction programs," the book says.

But it then states, a few paragraphs later, that the results of such energy-reduced restricted diets "are known to be poor and not long-lasting. So why is such an ineffective therapy the cornerstone of treatment? The Handbook of Obesity neglects to say."
(Taubes. Why We Get Fat. Page 37.)