Does diet-induced weight change effect anxiety in overweight and obese adults?

Anxiety is the most prevalent type of mental disorder and a significant health concern. Cross-sectional studies have detected a positive association between obesity and anxiety. What is less clear is whether weight loss can reduce anxiety. We sought to answer three questions: 1. Can weight loss improve symptoms of anxiety in the overweight and obese population? 2. Does the macronutrient content of energy-restricted diets that induce weight loss affect anxiety? 3. Is the change in anxiety related to the amount of weight lost? We investigated the findings from seven interventional studies, which induced weight loss by dietary intervention, in overweight and obese individuals, using established anxiety assessment tools. Mean weight loss ranged from 0.7 to 18.6 kg (SD 4.5) and in three of the studies, anxiety fell by 9.2% to 11.4% and did not change in four studies. When macronutrient content was considered, only one of four interventional studies and one pilot study reported a beneficial effect of a moderate-fat diet on anxiety. There appears to be no strong evidence to indicate that diet-induced weight loss has a beneficial effect on anxiety, however, none of the diet-induced weight loss studies assessed had a detrimental effect on anxiety.