Browsing by Author "Kuusisalo, Hanna"

Introduction: The research on the effect of plant-based diets is needed in order to promote sustainability and to recommend diets containing more plant-based and less animal protein, at population level. Objective: The aim of this thesis was to study how replacing animal protein sources with plant-based protein affects the intake of energy, protein, total fat and saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids and n-3 and n-6 fatty acids, carbohydrates and the dietary fiber. Study compliance was assessed on the basis of protein intake (17 E%). Materials and methods: A 12-week clinical intervention study was carried out at the Department of Food and Environmental sciences in the University of Helsinki in spring 2017. This thesis includes data from 132 participants. The participants were randomized in three different groups which differed in their protein sources (animal versus plant-based protein): Group 1: 70 % of animal and 30 % of plant-based protein; Group 2: 50 % animal and 50 % plant-based protein; Group 3: 30 % animal and 70 % plant-based protein. Participants kept food diary for 4 days, both before the intervention and on the 12th week of the intervention. The differences between the intake of the energy-yielding nutrients were compared between the groups with variance analysis and Bonferroni test, and within the groups with t-test. The compliance was determined based on the intake of protein on 12th week of the intervention. Results: Compared to the baseline, the intake of the protein decreased in group 3 and did not reach 17 E%. In groups 2 and 3 the intake of saturated fatty acids decreased (p<0,001) and the intake of polyunsaturated fatty acids (p<0,001), n-6 (p<0,001) and n-3 fatty acids (G2: p<0,001; G3: p=0,016) increased. The intake of dietary fiber increased in groups 2 and 3 (p<0,001). During the intervention the intake of protein in group 3 (14,3 E%) was lower compared to group 1 (17,6 E%) and group 2 (16,3 E%). Compared to group 1, the intake of n-3 -fatty acids in groups 2 (p=0,004) and 3 (p=0,024) was higher and the differences were statistically significant. There were statistically significant differences in the intake of saturated, polyunsaturated and n-6-fatty acids and dietary fiber between the groups and the differences were statistically significant. The intake of saturated fatty acids was highest in group 1 and lowest in group 3. The intake on polyunsaturated and n-6-fatty acids and dietary fiber was highest in group 3 and lowest in group 1. Conclusions: When animal protein sources were replaced with plant-based protein sources, the intake of dietary fiber and unsaturated fatty acids increased, while the intake of saturated fatty acids and protein decreased. When animal protein sources were replaced with plant-based protein sources, the quality of the diet changed to correspond better to the Finnish nutrition recommendations.