Role of Dietary Macronutrients and Fatty Acids in Obesity and Metabolic Risk in Older Adults

The aim of the study was to examine the role of dietary consumption of different types of fatty acids on metabolic risk factors and regional fat deposition in older men and women. We hypothesized that saturated fatty acid (SFA) intake, monounsaturated fatty acid (MUFA) and low intake of polyunsaturated fatty acids (PUFA) would be associated with markers of insulin resistance, hyperlipidemia, and hypertriglyceridemia. Sedentary, overweight and obese (body mass index: 29-48 kg/m²) adults (N=20) aged 45-78 years underwent two-hour oral glucose tolerance test, blood draw, DXA scan, and completed seven-day diet records. Subjects had low fitness levels (VO₂ max=23.5 ± 2.4 mL/kg/min) and high total body fat (43.5 ± 1.7%). The average macronutrient composition of the diet was high in fat as a percent of total kcal (35.5%). The ratio of MUFA to PUFA was associated with serum cholesterol (r=0.48, P=0.03) and tended to be associated with higher fasting glucose (r=0.42, P=0.06) and glucose at 120 min (r=0.43, P=0.06). PUFA intake as a percentage of fat intake was associated with lower serum cholesterol (r=-0.44, P=0.05). Therefore, dietary MUFA intake unbalanced by PUFA may confer increased risk for diabetes among obese, sedentary individuals. Future investigation of food sources, or context of dietary lipids, could lead to individualized dietary recommendations to promote healthy eating habits and potentially alter metabolic risk.