OBJECTIVE: To study the effect on weight loss in obese subjects by replacement of carbohydrate by protein in ad libitum consumed fat-reduced diets.
DESIGN: Randomized dietary intervention study over six months comparing two ad libitum fat reduced diets (30% of total energy) strictly controlled in composition: High-carbohydrate (HC, protein 12% of total energy) or high-protein (HP, protein 25% of total energy).
SETTING AND PARTICIPANTS: Subjects were 65 healthy, overweight and obese subjects (50 women, 15 men, aged 18–55 y) randomly assigned to HC (n=25), HP (n=25) or a control group (C, n=15). All food was provided by self-selection in a shop at the department, and compliance to the diet composition was evaluated by urinary nitrogen excretion.
MAIN OUTCOME MEASURE: Change in body weight, body composition and blood lipids.
RESULTS: More than 90% completed the trial. Weight loss after six months was 5.1 kg in the HC group and 8.9 kg in the HP group (difference 3.7 kg, 95% confidence interval (CI)(1.3–6.2 kg) P<0.001), and fat loss was 4.3 kg and 7.6 kg, respectively (difference 3.3 kg (1.1–5.5 kg) P<0.0001), whereas no changes occurred in the control group. More subjects lost >10 kg in the HP group (35 %) than in the HC group (9 %). The HP diet only decreased fasting plasma triglycerides and free fatty acids significantly.
CONCLUSIONS: Replacement of some dietary carbohydrate by protein in an ad libitum fat-reduced diet, improves weight loss and increases the proportion of subjects achieving a clinically relevant weight loss. More freedom to choose between protein-rich and complex carbohydrate-rich foods may allow obese subjects to choose more lean meat and dairy products, and hence improve adherence to low-fat diets in weight reduction programs.
About this article
Cite this article
Skov, A., Toubro, S., Rønn, B. et al. Randomized trial on protein vs carbohydrate in ad libitum fat reduced diet for the treatment of obesity. Int J Obes 23, 528–536 (1999). https://doi.org/10.1038/sj.ijo.0800867
- low-fat diets
- ad libitum
- cardiovascular risk factors
- blood lipids
- body composition
Effect of hypocaloric high-protein, low-carbohydrate diet supplemented with fennel on androgenic and anthropometric indices in overweight and obese women with polycystic ovary syndrome: A randomized placebo-controlled trial
Complementary Therapies in Medicine (2021)
The effects of pre-sleep consumption of casein protein on next-morning measures of RMR and appetite compared between sedentary pre- and postmenopausal women
British Journal of Nutrition (2021)
Effect of Protein Intake on Visceral Abdominal Fat and Metabolic Biomarkers in Older Men With Functional Limitations: Results From a Randomized Clinical Trial
The Journals of Gerontology: Series A (2021)
Effect of Increasing the Dietary Protein Content of Breakfast on Subjective Appetite, Short-Term Food Intake and Diet-Induced Thermogenesis in Children