A modelling approach to investigate the impact of consumption of three different beef compositions on human dietary fat intakes

Objective: To apply a dietary modelling approach to investigate the impact of substituting beef intakes with three types of alternative fatty acid (FA) composition of beef on population dietary fat intakes.

Design: Cross-sectional, national food consumption survey - the National Adult Nutrition Survey (NANS). The fat content of the beef-containing food codes (n 52) and recipes (n 99) were updated with FA composition data from beef from animals receiving one of three ruminant dietary interventions: grass-fed (GRASS), grass finished on grass silage and concentrates (GSC) or concentrate-fed (CONC). Mean daily fat intakes, adherence to dietary guidelines and the impact of altering beef FA composition on dietary fat sources were characterised.

Setting: Ireland.

Participants: Beef consumers (n 1044) aged 18-90 years.

Results: Grass-based feeding practices improved dietary intakes of a number of individual FA, wherein myristic acid (C14: 0) and palmitic acid (C16: 0) were decreased, with an increase in conjugated linoleic acid (C18: 2c9,t11) and trans-vaccenic acid (C18: 1t11; P < 0·05). Improved adherence with dietary recommendations for total fat (98·5 %), SFA (57·4 %) and PUFA (98·8 %) was observed in the grass-fed beef scenario (P < 0·001). Trans-fat intakes were increased significantly in the grass-fed beef scenario (P < 0·001).

Conclusions: To the best of our knowledge, the present study is the first to characterise the impact of grass-fed beef consumption at population level. The study suggests that habitual consumption of grass-fed beef may have potential as a public health strategy to improve dietary fat quality.