To Örebro University

Introduction: Some dietary patterns have been linked to having a positive influence on health parameters connected to disease development. One explanation behind this is the health mediating effects of the macronutrient composition. Therefore, the aim of this study was to investigate relationships between total intake of protein, fat, and carbohydrates and metabolic health parameters connected to disease development in older women and to assess the effect of isocaloric macronutrient replacement on the same health parameters.

Method: 116 healthy older women aged 65-70 years were included. Body weight, waist circumference, blood pressure and metabolic blood markers (triglycerides, cholesterol, high-density lipoprotein, low-density lipoprotein, oxidized low-density lipoprotein, and fasting glucose) were assessed. Dietary intake was assessed using food records. Partial correlation was used for the analysis of relationships between total macronutrient intake and health parameters. Effect of macronutrient isocaloric substitution was analysed by linear regression. All analyses were adjusted for total energy intake.

Results: Significant reductions in waist circumference (β = -3.5, p = 0.03) and BMI (β = -1.4, p = 0.02) were observed when 10 E% of carbohydrates replaced 10 E% of fat. Significant reductions in BMI (β = -3.4, p = 0.04) were also observed when 10 E% of protein replaced 10 E% of fat. Regarding systolic blood pressure, significant reductions were observed when 10 E% protein replaced 10 E% of fat (β = -14.9, p = 0.05) and 10 E% of carbohydrates (β = -16.3, p = 0.02).

Conclusion: This study shows that macronutrient composition has a significant effect on waist circumference, BMI and systolic blood pressure in older women. This supports public health strategies highlighting the importance of macronutrient composition of diet for a healthier aging.