Effect of Different Fatty Acids on Metabolic Rate in Overweight Women

A double-blind, randomised, placebo-controlled intervention trial designed to evaluate whether fish oil supplementation can positively impact on metabolic rate in overweight women. Forty volunteers will be recruited through public advertisements. Prior to the commencement of the study volunteers will complete a series of questionnaires and tests designed to assess general health, diet history and exercise habits. Participants will be randomly allocated to consume 5 x 1g capsules per day containing either vegetable oil (control group) or fish oil for the duration of the study. Participants in the control group will receive 5 x 1g capsules of vegetable oil. For participants randomised to the fish oil group, the amount of fish oil provided will be based on participants’ total body weight. Participants will receive 2-5 fish oil capsules (each capsule of fish oil contains 600mg of long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) with the remainder as vegetable oil, providing a total of 5 capsules per day. Possible combinations are therefore; Group 1: up to 65kg (BMI 25-27.5) --> 2 fish oil, 3 placebo, Group 2: 65.1-75kg (BMI 27.6-30) --> 3 fish oil, 2 placebo, Group 3: 75.1-85 (BMI 30.1-32.5) --> 4 fish oil, 1 placebo, Group 4: 85kg and over (BMI 32.6-35) --> 5 fish oil, no placebo. A supplement diary will be used to assess compliance. Participants will attend two study visits at baseline (week 0) and at completion of the intervention (week 6). During these visits each participant will have a series of non-invasive measurements taken which include height, weight, resting energy expenditure, fat oxidation and body fat. Blood samples will be collected at both visits and assessed for erythrocyte saturation of two key fatty acids, DHA and EPA