Abstract
BACKGROUND: Previously, we found that healthy underweight (HU) subjects, with BMI < 18.5, eat about 12% less food (by calories) each day. It is presently unclear whether this lower intake is associated with them making food choices that provide high satiation and satiety. METHODS: Using 7-day photographic records of food intake, we analyzed 52 HU and 50 normal-weight participants. RESULTS: We included 52 HU and 50 normal-weight participants in the final analysis. HU individuals ate 25% fewer calories than normal-weight individuals. Their intake included a higher % of rice (p = 0.0013) and vegetables (p = 0.0006) and a lower % of livestock meat (p = 0.0007), poultry meat (p < 0.0001), and starchy roots (p = 0.0015), compared with the normal-weight population. The percent energy from carbohydrates was significantly higher (p = 0.0234), and the % energy from fat was significantly lower (p < 0.0001) in the HU group, with no difference in the % energy from protein. HU individuals sourced more of their protein from plants. Dietary patterns were grouped into three clusters, with 24 individuals grouped into cluster 1 (87.5% normal-weight population), 28 individuals into cluster 2 (64.3% normal-weight group), and 50 individuals into cluster 3 (78% HU group). CONCLUSIONS: The HU group ate less overall and had proportionally more rice and vegetables and less poultry and livestock meat, starchy roots, and drinks. With respect to macronutrients, they also ate a greater % carbohydrates and less % fat, and they sourced more of their protein intake from plant sources. HU individuals did not follow a low-carbohydrate lifestyle.