Obesity
Conditions
Keywords
Diet, Ketogenic, Weight Loss, Body Weight
Brief summary
Low-carb ketogenic diets have become extremely popular because of large weight loss in the short-term. Yet their potential benefits in preventing long-term weight regain have not been assessed in large scale studies. The aim of this study is to determine the effect of a low-carbohydrate (CHO) ketogenic diet, compared with an isocaloric balanced diet, on the maintenance of weight loss. The secondary aim is to investigate the impact of both diets on appetite. Adults with obesity (30\<BMI\<40 kg/m2), will first undergo 4 weeks of a very-low energy diet aimed at inducing 5-10% weight loss and then will be randomized to two different weight maintenance diets for 1 year. One will be a low-CHO ketogenic diet (50 g CHO/day) plant-based (e.g. with less animal protein and more plant-based), and the other a diet following the Norwegian Health Directorate recommendations. Only conventional foods will be used in both diets.
Interventions
BEHAVIORALKetogenic weight loss maintenance diet
The ketogenic weight loss maintenance group will undergo in a ketogenic diet (50 g CHO/day) plant-based for 1 year.
BEHAVIORALIsocaloric balanced weight loss maintenance diet
The isocaloric balanced weight loss maintenance group will undergo in a diet following the recommendations from the Norwegian Health Directorate for 1 year.
Sponsors
St. Olavs Hospital
Norwegian University of Science and Technology
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* weight stable over the last three months (\<2 kg) * not currently dieting to lose weight * inactive lifestyle (less than 150 min of physical activity weekly. * Given that some of the variables of interest have been shown to be affected by the phase of menstrual cycle in normally ovulating women, namely appetite and resting metabolic rate, only women taking oral contraceptives, with regular menstrual cycles or post-menopausal will be included in the study
Exclusion criteria
* pregnancy * breast-feeding * drug or alcohol abuse within the last two years * clinically significant illness including diabetes, gastrointestinal (particularly cholelithiasis), kidney (GFR \<60) or liver disease, osteoporosis (T-score \<-2.5) and osteopenia (T-score \<-1.5) * treatment with antiosteoporotic drug * depression or other psychological disorders * eating disorders * milk intolerance * current medication known to affect appetite/metabolism or induce weight loss. * a planned surgery during the study period * participating in another research study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Body weight regain | Body weight changes at 1-year intervention | Body weight will be measured at baseline, at week 5, at 6 months, and at 1 year |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Bone mineral density | Bone mineral density changes at 1-year intervention | Bone mineral density will be measured by Dual-energy X-ray absorptiometry (DXA) at baseline, at 6 months, and at 1 year |
| Fasting lipid profile | Lipid profile changes at 1-year intervention | Blood sampling in fasting to measure lipid profile (plasma concentration of total cholesterol, triglycerides, high-density lipids (HDL), low-density lipids (LDL) at baseline, at 6 months, and at 1 year |
Countries
Norway
Outcome results
None listed