Shively, C.A. et al. Obesity 27, 777–784 (2019)

Studies based on human self-reporting suggest that plant- and lean protein-rich Mediterranean diets are better for one’s health—or at least one’s waistline—than sugary, saturated-fat heavy Western diets. A randomized, long-term controlled diet study in nonhuman primates reaches similar conclusions.

The researchers at Wake Forest University established baseline obesity and metabolic measures in socially housed, middle-aged female macaques after 7 months on typical monkey chow. They then divided those animals into two experimental groups: one was fed a Mediterranean-like diet; the other, a Western-like one. The animals were followed for 31 months, a span representing about 9% of a macaque’s life. Though baseline measures were similar and the animals on each diet could eat as much as they wanted, the Mediterranean macaques ended the study with lower BMIs, less body and liver fat, and lower triglyceride levels than Western-fed counterparts.