Vegetarian Diets along with Regular Exercise: Impact on High-Density Lipoprotein Cholesterol Levels among Taiwanese Adults.

High-density lipoprotein cholesterol (HDL-C) is important for improving risk estimates of atherosclerotic cardiovascular disease. We investigated the effect of omnivore and diverse vegetarian diets in connection with exercise on HDL-C. Historical data of 9588 biobank participants (4025 exercisers and 5563 non-exercisers) aged 30-70 years were categorized as omnivores (n = 8589), former vegetarians (n = 544), lacto-ovo vegetarians (n = 417), and strict vegetarians (n = 38). We used multiple linear regression for analyses. HDL-C levels were higher in exercisers compared to non-exercisers. Compared with omnivores, strict vegetarians had decreased levels of HDL-C ( = -5.705; = 0.001) followed by lacto-ovo vegetarians ( = -3.900; < 0.001) and former vegetarians ( = -0.329; = 0.475). The test for trend was significant ( < 0.001). After categorization by exercise modalities, the value was -13.984 for strict vegetarians, -4.419 for lacto-ovo vegetarians, and -1.864 for former vegetarians, respectively ( < 0.05). There was an interaction between diet and exercise ( = 0.009). Omnivores who exercised regularly had significantly higher HDL-C, whereas strict vegetarians who exercised regularly had significantly lower HDL-C. In summary, strict vegetarian diets in conjunction with regular exercise might not serve as healthful behaviors to be implemented in everyday life considering the negative impact on HDL-C.