Weight Loss Intervention With Lean Muscle Mass Retention

Overweight and obesity (i.e., excess body fat) is a worldwide health problem, which predisposes individuals to various metabolic diseases. Weight loss through lifestyle modifications such as dietary calorie restrictions and/or exercise are effective approaches to reduce excess body fat. However, lean muscle mass loss is often an undesired outcome associated with weight loss, which should be avoided, particularly in older adults, who are also faced with declining anabolic responses to dietary protein intake. Given the increased interest and popularity of plant-based diets, in this study we will compare two distinct calorie-restricted, weight loss diets, both supplemented with weekly exercise, predominantly consisting of either plant-based proteins or animal-based proteins on changes in total body weight, body fat and lean muscle mass, as well as associated changes in metabolic health.

Inclusion Criteria:Male or FemaleChinese ethnicityAge between 40 to 69 yearsAble to give informed consentBody Mass Index (BMI) between 23.0 to 32.5 kg/m2Exclusion Criteria:SmokingHaving allergies or intolerances to any common food ingredients including eggs, fish, milk, peanuts, and tree nuts, shellfish, soya, wheat, gluten, cereal, fruits, dairy products, meat, vegetable, sugar and sweetener, natural food colourings or flavourings, etcFollowing special diets or having intentional dietary restrictions (e.g, vegetarians/vegans)Not willing to stop consumption of probiotic or prebiotic supplements within 4 weeks prior to start of study if currently taking these, as well as during study participationNot willing to adhere to diet modification as in the study protocolNot willing to adhere to the exercise regime as in the study protocolTaking part in strenuous physical activitiesNot willing to stop any strenuous activity during or within 24 hours of test days (for those actively participating in sports at the competitive and/or endurance levels)Having glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency)Having alcohol consumption on > 4 days per week with ≥ 6 alcoholic drinks per weekHaving sustained elevation of blood pressure (>160/95 mm Hg)Having previously undergone any gastrointestinal surgery or having history of gastrointestinal disordersHaving a history of heart, liver, kidney, blood disorders (e.g., thalassemia) or thyroid dysfunctionsDiabeticHaving history of tuberculosis, HIV, Hepatitis B or Hepatitis C infectionsHaving any prescription medication or any other alternative medicines or supplements which may interfere with study measurements in the in the opinion of the study investigatorsHaving antibiotics or suffering from diarrhea within the last 3 monthsHaving donated blood within 4 weeks of study participationHaving poor veins or having history of severe vasovagal syncope (blackouts or fainting) from blood drawsHaving more than 5% weight loss or gain over the past 3 monthsHaving metallic implants, pacemaker in the bodyHaving claustrophobiaHaving a musculoskeletal injury, joint or peripheral vascular disease sufficient to impede exercise (such as hip arthritis, foot, ankle problems or pain)Having severe exercise-induced asthmaStaff of Wilmar International and/or Singapore Institute of Food and Biotechnology Innovation (SIFBI)For female volunteers: menstruation within past 12 months or being on hormone replacement therapy