Will Chocolate Help You Lose Weight?


In news that is sure to make the people at Mars Inc. absolutely giddy, a study published this week in the Archives of Internal Medicine suggests that chocolate consumption could help people control their weight. According to the study's authors, "Adults who consumed chocolate more frequently had a lower BMI than those who consumed chocolate less often."

Chocolate is definitely tasty, especially when slathered over mini donuts; that's reason enough to consume it in moderation. But if you need a science-y reason to eat a Hershey bar, you're still out of luck. We have very little evidence to suggest that chocolate will help you lose weight -- at least for now.

The study involved 1,018 men and women between the ages of 20 to 85, who were free of cardiovascular disease, diabetes, or extreme LDL (low-density lipoprotein cholesterol) levels. Researchers gathered data on chocolate consumption through food frequency questionnaires which asked participants "How many times a week do you consume chocolate?" Calorie intake and exercise didn't explain the lower BMI of people who more frequently consumed chocolate, according to the study.

Results like this aren't implausible, as previous studies have suggested that chocolate may confer some health benefits on those who indulge, like higher insulin sensitivity and lower blood pressure. But science usually isn't that simple. Critics have blasted food scientists for previously claiming that chocolate is a doer of health miracles, because improvements in metabolic health and weight loss are typically due to major dietary changes, not any particular food people may or may not eat.

And since the available research on the subject is rather limited, researchers have urged caution before linking chocolate consumption to any particular health benefit. It's more likely that healthier people just happen to eat more chocolate, not that people who eat chocolate are healthier than the rest of us.

Additionally, like most health research that makes headlines, this study was observational in nature. So even if its conclusion is correct, the results have to be replicated in a clinical setting. As the authors rightly point out, "A randomized trial of chocolate for metabolic benefits in humans may be merited." 

But there's another reason the results raise a red flag. The data for the study came from food surveys, which many researchers have also argued are not awfully reliable as a means of determining what and how much people eat. Could you accurately track how much of any given food you eat each week? And how do you know? Those aren't rhetorical questions, either. Now, consider that studies like the one discussed here usually involve hundreds or thousands of people. It's hard to know in these instances if the numbers are reliable.

And perhaps most importantly, the researchers didn't control for carbohydrate consumption, which even more researchers and science writers have argued deserves a lot of the blame for the epidemic of obesity and related diseases in this country. A diet high in carbohydrates increases blood sugar, which in turn encourages fat storage. That could definitely confound the results of this study.

Chocolate is a delicious treat that should be eaten for no other reason than the fact it is a delicious treat. But like other treats, such as alcohol, consume chocolate sparingly, eat well, exercise, and you'll probably be in good shape.