The Atkins Diet Could Make You Hate Life

Photograph of a woman cutting steak by Getty Creative Images.

• 
• |
• 
• |
• |
• 4

In the duel between the two most popular diets, it’s a draw: People who eat a lot of carbohydrates and little fat or those who follow an Atkins-style regime of few carbs and high fat will lose roughly the same amount of weight, according to the latest research. But if you care about your feelings as well as your flab, a new study on mood published this week in the Archives of Internal Medicine found a convincing distinction between the two approaches.

Dieters who ate low-carb, high-fat foods for a year were crankier than their peers who followed the more conventional diet. Of course, few people on a diet—no matter the type—are cheery. They have to adhere to strict plans, deal with hunger, swear off foods they like, and, especially if they’re on an Atkins-style program, contend with fatigue, bad breath, and constipation. But the study’s authors speculate that other reasons—perhaps social or chemical—are behind the low-carb mood shift. This new information and future long-term studies could provide clues about why some diets succeed while others fail.

Researchers from Australia’s national science agency randomly placed about 100 dieters into two groups and instructed them to eat roughly the same amount of calories (between 1,400 and 1,700) per day. The low-carb group ate a diet comprised of 4 percent carbs, 61 percent fat, and 35 percent protein, compared with the high-carb group, who consumed 46 percent carbs, 30 percent fat, and 24 percent protein. The majority of participants, who lost about 30 pounds each in the year, experienced a mood lift at the beginning of the trial, presumably because they were pleased with their progress. But by the eighth week, the low-carb group had lost their happiness boost and reported feeling angry, depressed, and confused. The high-carb group, however, still felt good.

At first glance, it might seem as if the Atkins diet is more indulgent. By giving up carbs, you’re mostly left with protein and fat. As long as you avoid grains, potatoes, beans, sugar, milk, and fruit, you can eat unlimited amounts of triple-cream Brie and marbled rib-eye. Even though some experts recommend a lower-fat version with more allowances for carbs, they credit the Atkins diet’s high level of protein, which takes longer to digest than carbs, for making programs easier to follow. One study in The Journal of Nutrition found that dieters who ate more protein reported less hunger and a “greater degree of diet satisfaction.”

But that’s in the short-term. The authors of the Archives of Internal Medicine study suggest that over the long run, dieters who eat less than 60 grams of carbs per day experience either social stigma from rejecting the bread basket one too many times or a change in brain chemistry that kills the buzz. The social explanation seems thin, since people in both camps likely had to endure a year’s worth of questions asking why they couldn’t share a slice of high-calorie birthday cake.

The more compelling hypothesis involves serotonin, a neurotransmitter that regulates mood and sleep. Research from the 1970s by MIT neuropharmacologist Richard Wurtman found that eating carbohydrates creates serotonin. Low-carb dieters therefore have less of the chemical and suffer from anxiety, reduced ability to cope, inappropriate anger, and a “chronic low-level depression,” insists his wife, Judith Wurtman, author of The Serotonin Power Diet and a biologist who ran weight loss programs at the Harvard-affiliated McLean Hospital. Women are especially vulnerable to serotonin fluctuations, since they have only three-fourths of the amount in their brains that men do and are more prone to depression anyway, she says, explaining that serotonin also controls appetite. Her claim: Eating more carbs boosts people’s moods and helps them eat less and lose weight.