Extended calorie restriction suppresses overall and specific food cravings: a systematic review and a meta-analysis.

BACKGROUND: Multiple studies have concluded that calorie restriction for at least 12 weeks is associated with reduced food cravings, while others have shown that calorie restriction may increase food cravings. We addressed this ambiguity in a systematic review and meta-analysis.

METHODS: We searched for studies conducted on subjects with obesity, implemented calorie restriction for at least 12 weeks and measured food cravings pre-intervention and post-intervention. Our final eight studies mostly used the Food Craving Inventory. Other comparable methods were converted to a similar scale. We used the duration ≥12 weeks, but closest to 16 weeks for studies with multiple follow-ups and performed DerSimonian-Laird random-effects meta-analyses using the 'metafor' package in r software.

RESULTS: Despite heterogeneity across studies, we observed reductions in pooled effects for overall food cravings (-0.246 [-0.490, -0.001]) as well as cravings for sweet (-0.410 [-0.626, -0.194]), high-fat (-0.190 [-0.343, -0.037]), starchy (-0.288 [-0.517, -0.058]) and fast food (-0.340 [-0.633, -0.048]) in the meta-analysis. Baseline body weight, type of intervention, duration, sample size and percentage of female subjects explained the heterogeneity.

CONCLUSIONS: Calorie restriction is associated with reduced food cravings supporting a de-conditioning model of craving reductions. Our findings should ease the minds of clinicians concerned about increased cravings in patients undergoing calorie restriction interventions.