Relationship of the reported intakes of fat and fatty acids to body weight in US adults

Authors: Raatz, Susan; Conrad, Zachary; JOHNSON, LUANN - University Of North Dakota; Picklo, Matthew; Jahns, Lisa

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2017
Publication Date: 4/28/2017
Publication URL: https://handle.nal.usda.gov/10113/5695446
Citation: Raatz, S.K., Conrad, Z.S., Johnson, L., Picklo, M.J., Jahns, L.A. 2017. Relationship of the reported intakes of fat and fatty acids to body weight in US adults. Nutrients. doi:10.3390/nu9050438.

Interpretive Summary: Experimental studies indicate that the fatty acid composition of dietary fats may affect body weight by modifying energy expenditure and other factors like the use of fat as fuel and effects on satiety. The purpose of this study was to compare intakes of energy, macronutrients, and individual fatty acids across body mass index (BMI) categories for the US adult population by sociodemographic groups. Reported dietary intake data from National Health and Nutrition Examination Survey from 2005-2012, representing nearly 20,000 Americans, were analyzed. Overall, we found that the intake of carbohydrate, protein, total fat, total saturated fat, long-chain saturated fatty acids, and monounsaturated fatty acids increased with increasing body weight. The medium chain saturated fatty acid lauric acid, total and individual polyunsaturated fatty acids were not associated with BMI. Demographic differences in these relationships were observed between non-Hispanic Black, non-Hispanic White and Mexican-American groups. These data indicate that the intake of specific fatty acids is related to increasing body weight and that the influence of demographic modifiers upon these relationships warrants more study.

Technical Abstract: Dietary fat composition may modulate energy expenditure and body weight. Little is known about the relationship between fatty acid intake and body weight at a population level. The purposes of this study were to compare intakes of energy, macronutrients, and individual fatty acids across BMI categories for 1) the US adult population and, 2) by sociodemographic groups. Reported dietary intake data from NHANES, WWEIA surveys in years 2005-2012 were analyzed. Overall, we found that the reported intake of carbohydrate, protein, total fat, total saturated fat (as well as long-chain saturated fatty acids 14:0-18:0), and MUFA were positively associated with BMI; while lauric acid (a medium chain saturated fatty acid, 12:0) and total PUFA (as well as all individual PUFAs) were not associated with BMI. Non-Hispanic blacks demonstrated a negative association between BMI and energy intake and a positive association between total PUFA, LA, ALA and BMI., Individuals with less than a high school education showed a negative association between BMI and DHA. Mexican-Americans reported intakes with no association between BMI and energy, any macronutrient, or individual fatty acid. These findings support those of experimental studies demonstrating fatty acid dependent associations between dietary fatty acid composition and body weight. Notably, we observed divergent results for some sociodemographic groups which warrant further investigation.