Changes in blood lipid concentrations associated with changes in intake of dietary saturated fat in the context of a healthy low-carbohydrate weight-loss diet: a secondary analysis of the Diet Intervention Examining the Factors Interacting with Treatment Success (DIETFITS) trial

In the DIETFITS trial, 609 generally healthy adults, aged 18-50 years, with BMIs of 28-40 kg/m2 were randomly assigned to a healthy low-fat (HLF) or healthy low carb (HLC) diet for 12 months. Participants consumed an average of 12-18% of calories from SFA. An increase of %SFA, without significant changes in absolute saturated fat intake, over 12 months was associated with a statistically significant decrease in triglycerides in the context of a weight-loss study in which participants simultaneously decreased carbohydrate intake. The association between increase in %SFA and decrease in triglycerides was no longer significant when adjusting for 12-month change in carbohydrate intake, suggesting carbohydrate intake may be a mediator of this relationship.