A just published study found that dieters following high-fat diets such as the Atkins and South Beach were considerably more depressed and irritable than those on low-fat diets one year after starting the diet.
It’s no secret that the overwhelming majority of weight loss programs ultimately fail, but that failure doesn’t necessarily come from lack of willpower. According to a study of 17,000 failed dieters conducted by Dr. Roger Gould at UCLA and cited in his book, Shrink Yourself, “virtually all of [the 17,000 subjects in the study] relapsed because of emotional issues.”
Given the close link between emotional states and the propensity to break the diet, it makes sense that those who stay happy and stable when dieting will stick to the regimen better than their more volatile peers. And so, anyone longing to lose weight might be interested in new research finding that grumpiness runs rampant among those on high-fat, high-protein, low-carb diets. In fact, in a study just published by the Commonwealth Scientific and Industrial Research Association in Adelaide, Australia, dieters following high-fat diets such as the Atkins and South Beach were considerably more depressed and irritable than those on low-fat diets one year after starting the diet. (They also had a pronounced desire to run at night with the wolves and howl at the moon, but that’s a different study.)
The researchers recruited 106 obese and overweight people and randomly assigned them to follow either a low-fat or low-carbohydrate diet for a year. Both diets restricted calories to 1,433 to 1,672 daily. At several intervals throughout the study, the researchers subjected the participants to the Spielberger State Anxiety Inventory, the Beck Depression Inventory, and the Profile of Mood States. These instruments test for anger and hostility, confusion, overall disturbed mood, and depression. After eight weeks, dieters in both groups showed increases in positive mood and happiness. Previous studies found similar results — dieting in general improves outlook, but those previous studies only measured mood early on in the dieting process. In this case, researchers also took mood measurements a year into the diet, and by then, only subjects on the low-fat diet remained on the sunnier side.
A large number of the original subjects dropped out before completing the year — 41 in all. Of those who remained, participants lost an average of 30 pounds — in both groups. In spite of the weight loss, though, study director Grant Brinkworth expressed concern that over time, all improvements would be eroded if participants on the low-carb diet remained unhappy.
“Altered mood has been shown to influence interpersonal behavior and, therefore, the consumption of a very low-carbohydrate diet may have psychosocial consequences for interpersonal behavior and relationships,” he said. “…one of the factors that may pose risk for poor long-term weight maintenance may be eating in response to negative emotions and stress. Therefore, since negative mood may promote overeating, this suggests that consumption of a very low-carbohydrate diet over an even longer period beyond one year may have implications for maintaining dietary habits and weight loss maintenance.”
What is it about the low-carb diet that brings out the Scrooge? According to Dr. Brinkworth, “Potential explanations include the social difficulty of adhering to a low-carbohydrate plan, which is counter to the typical western diet full of pasta and bread; the prescribed, structured nature of the diet; or effects of protein and fat intake on brain levels of serotonin, a neurotransmitter related to psychological functioning.”
The report, published in the Archives of Internal Medicine, devotes considerable space to discussing the first of Dr. Brinkworth’s explanations — the pasta and bread factor. “The [low carb] diet being so far removed from normal dietary habits may have created a significant challenge for participants, leading to the possibility of food preoccupation, social eating impairment, and dysphoria” says the report.” And, as Dr.Kristin D’Anci of Tufts University, a food/mood expert, explains, low-carb diets rely on calorie dense foods, which means you get far less on your plate to stay within the calorie limits. Those in the other group, though, “…are getting more to eat, and that makes people happy. This is the kind of thing where it doesn’t disrupt your life so much.” In other words, the low-carb group got grumpy because they got too little grub and no fun foods.
On the other hand, Dr. Brinkworth also refers to the way excessive protein and fat affect serotonin levels. Serotonin levels drop on low-carb diets, and low serotonin levels link to depression.
But mood and sustainability hardly constitute the whole problem with low-carb diets. As I’ve written before, excluding carbohydrates means excluding some of the foods richest in essential phytochemicals: fruits, leafy greens, and sprouts. Your body needs these carbs to function optimally. Plus, low-carb diets generally depend on high consumption of meat, which overtaxes the liver, destroys beneficial bacteria in the gut, generates an abundance of cancer-promoting acidity, increases vulnerability to osteoporosis, and creates an imbalance of Omega 6 to Omega 3 fats. If the meat isn’t organic, is grain fed, or if it’s been treated with antibiotics and growth hormones, so much the worse.
Bottom line: Balanced diets that avoid refined and high-glycemic carbs and that limit dairy and meat work best for the waistline, for overall health, and apparently, for psychological well-being. There is a name for this eating regimen: It’s called the Mediterranean Diet.