Counting calories and limiting portion sizes are hallmarks of the so-called starvation diet trend.

However, according to a new study published in the Journal of the American Medical Association, these diets will not help participants lose weight in the long run.

Instead, the study found that the best ways of losing weight were cutting back on sugar, highly processed foods, and refined grains. The study also recommended eating plenty of fruit and vegetables.

These results bore out whether participants took part in a low-fat or low-carbohydrate diet.

Uniquely, this study did not tell participants how much food they could eat. Instead, those taking part were encouraged to eat as much as they needed to feel full.

What the study said:

The study was led by Christopher Gardner, the director of nutrition studies at the Stanford Prevention Research Center. Speaking to the New York Times, he explained the findings of the study in detail:

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“We really stressed to both groups again and again that we wanted them to eat high-quality foods… we wanted them to minimize added sugar and refined grains and eat more vegetables and whole foods. We said, ‘Don’t go out and buy a low-fat brownie just because it says low fat. And those low-carb chips – don’t buy them, because they’re still chips and that’s gaming the system.'”

“A couple weeks into the study people were asking when we were going to tell them how many calories to cut back on. And months into the study they said, ‘Thank you! We’ve had to do that so many times in the past.'”

“I think one place we go wrong is telling people to figure out how many calories they eat and then telling them to cut back on 500 calories, which makes them miserable. We really need to focus on that foundational diet, which is more vegetables, more whole foods, less added sugar and less refined grains.”

Why it matters:

The trial was a large and expensive one for its kind. Over 600 participants took place and overall funding was over $8m.

The study turned the idea that different people need different diets on its head. This idea is a modern phenomenon based on the idea that people should be recommended different diets depending on their genetics and tolerance for fat or carbs.

The study found that notion is almost entirely redundant. Cutting back on sugar, processed foods, and refined grains is a diet plan that works for everyone, according to the study.

Essentially, the study found that the key to losing weight is diet quality. The quantity of food cut out is not what helps people lose weight.

In addition, most participants in the study were able to lose weight without increasing the amount they exercised.

However, Gardner did explain that eating less calories ultimately does help. Most participants in the study were eating fewer calories by the end of the study.

But, he explained, a reduction in calories has to come within a context of changing a dieter’s relationship to food, not just calorie counting for the sake of weight loss.

The success of the study came down to changing the way participants consumed food. By the end of the study, participants reported that they were sitting down for meals with their family more.

They also said they no longer ate in cars or in front of the television.

Over a year, the participants in the study lost, on average, 13 pounds in the low-carb group and 11.7 pounds in the low-fat group.

Both groups also saw reductions in waist sizes, body fat, and blood sugar and blood pressure levels.


The study did push back against the ingrained notion of calorie counting in dieting. However, its secondary goal was to test the hypothesis that different genetics require different types of diets. The study found no evidence to suggest this is the case.

The researchers tested DNA samples from each of the participants. They used these to examine genetic variants which influence the metabolism. There is no evidence that peoples’ genetic make-up as any impact on dieting.

That will come as a disappointment to the dozens of companies who’ve sprung up around the world claiming to offer dietary advice based on the subject’s genetic information.