Mind Over Milkshake: The Placebo Effect in Diet and Weight Management
The placebo effect is commonly seen in studies on medications and medical treatments. Although there are typically no actual biological changes, the placebo effect has been shown time and time again to improve individuals’ feelings of well being and perceptions of health. In addition to drug studies, we see the placebo effect playing out in research on diet and food. This article in the Wall Street Journal provides some great examples of the placebo effect as it pertains to health interventions. The story highlights a study by researchers at Yale demonstrating the impact of the placebo effect on appetite via production of a peptide in the stomach called ghrelin. Grehlin alerts the body that it is time for food and its production slows as calories are consumed. This particular study showed that ghrelin levels were directly related to the number of calories study participants perceived they were consuming. Two groups were provided with the same milkshake that amounted to 380 calories. One group was told that they were drinking an “indulgent” milkshake containing 620 calories and the other group was informed that the milkshake was “sensible”, contributing only 140 calories. Interestingly, ghrelin levels responded in each individual as they would if that person had consumed the amount of calories they thought they were consuming (not the actual amount they consumed). These findings support the idea that the placebo effect has strong implications in appetite regulation and ultimately, weight management. This may be why some individuals report gaining weight while on a diet.