None listed
Conditions
Brief summary
Maintaining a healthy body weight is important as obesity is linked to diseases such as diabetes, heart disease, kidney disease, liver disease, and some cancers. In theory, weight loss can be achieved by simply reducing food intake and increasing exercise. In reality, many people struggle to maintain a healthy body weight. Many people find following a weight-loss regime to be very difficult in the long term when feelings of hunger and the desire to eat increase during periods of dieting. While there are plenty of weight-loss diets being advertised, there are two which are particularly popular with the general public: (i) the ‘high-protein diet’ and (ii) the ‘low-carbohydrate diet’. A high-protein weight-loss diet has been claimed to reduce hunger, increase energy expenditure, and retain muscle mass while helping to lose body fat. However, pushing up the protein content of your diet, means that you have to decrease either the carbohydrate or fat content, otherwise you will start to overeat, and possibly even gain weight. While the success of the ‘high-protein diet’ has been well documented in scientific articles, it has puzzled many researchers as to whether it is increasing to high-protein or decreasing to low-carbohydrate/low-fat that actually promotes the weight loss. Therefore, this study is designed to compare the difference in weight loss achieved using a ‘high-protein’ or a ‘low-carbohydrate’ low-energy diet for 8 weeks.
Interventions
Participants will be randomised to follow either a High-Protein Normal-Carbohydrate (HPNC), High-Protein Low-Carbohydrate (HPLC), Normal-Protein Normal-Carbohydrate (NPNC) or Normal-Protein Low-Carbohydrate (NPLC) Low-Energy Diets (LED) for 8 weeks. The target macronutrient compositions are: (i) 50/40/10 en% of protein/carbohydrate/fat for HPNC; (ii) 50/28/22 en% of protein/carbohydrate/fat for HPLC; (iii) 35/40/25 en% of protein/carbohydrate/fat for NPNC; and (iv) 35/28/38 en% of protein/carboh
Participants will be randomised to follow either a High-Protein Normal-Carbohydrate (HPNC), High-Protein Low-Carbohydrate (HPLC), Normal-Protein Normal-Carbohydrate (NPNC) or Normal-Protein Low-Carbohydrate (NPLC) Low-Energy Diets (LED) for 8 weeks. The target macronutrient compositions are: (i) 50/40/10 en% of protein/carbohydrate/fat for HPNC; (ii) 50/28/22 en% of protein/carbohydrate/fat for HPLC; (iii) 35/40/25 en% of protein/carbohydrate/fat for NPNC; and (iv) 35/28/38 en% of protein/carbohydrate/fat for NPLC. Furthermore, the LED is aimed to provide approximately 40% of their daily energy requirements estimated using the Harris-Benedict Equation to generate an energy deficit for weight loss. The LED will be achieved through the consumption of 2 servings Cambridge Meal Replacements in combination with 2 home-prepared meals (breakfast and dinner) every day for a period of 8 weeks. This trial will provide the Cambridge Meal Replacements to the participants at no cost but the participants are required to buy the food ingredients to prepare their home-prepared meals while adhering to our meal plans. The participants will attend a face-to-face group consultation at the Human Nutrition Unit, University of Auckland with a Registered Dietitian (RD) before the intervention is commenced and once every two weeks (Week 2, Week 4 and Week 6 after the intervention is commenced) to promote adherence to the diets. The participants will also complete a 4-day food diary and a 24-hour urine collection at baseline, 4 weeks after the intervention is commenced and 8 weeks after the intervention is commenced to check for compliance.
Sponsors
The University of Auckland Research Office
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
i. Females aged between 18 and 65 years. ii. Obese (BMI 30 kg/m2 - 45kg/m2) with a maximum body weight of 130kg iii. Otherwise healthy
Exclusion criteria
i. Recent body weight loss/gain >5% within previous 3 months ii. Currently taking part in an active diet program iii. Current medications or other conditions known to affect body weight and appetite iv. Previous bariatric surgery v. Diagnosed with impaired liver or kidney function vi. Significant current disease such as type 2 diabetes, cardiovascular disease, or cancer; or digestive disease including inflammatory bowel syndrome/disease (IBS/D), ulcerative colitis (UC), Crohn's disease vii. Systolic blood pressure greater than or equal to 160 mmHg and/or diastolic blood pressure greater than or equal to 100mmHg viii. Depression or any other anxiety disorder known to affect appetite ix. Unable to consume food items included in the study, or hypersensitivities or allergies to these foods (based on Food Preference Questionnaire) x. Smokers or ex-smokers who have given up smoking for less than 6 months xi. Pregnant or breastfeeding women xii. Unwilling/unable to comply with the study protocol
Outcome results
None listed