Abstract
Recently, attention has been paid to the effects of certain nutrients on body weight. High-protein (HP) diets are recommended, and high-carbohydrate (HC) diets are discouraged. However, HP is costly, and recently, some adverse effects of prolonged HP diets have been reported, involving risk factors for coronary artery, kidney, bone, and liver disease and other effects. Given this background, the question arises whether an HP diet is appropriate for healthy young people with normal body mass indices, and so we compared it with an HC diet in such individuals. We recruited 20 healthy women subjects with normal body weight and formed 10 pairs matched by energy intake, physical activity, height, weight, living conditions, and other factors. One member of each pair was then randomly assigned to 1 of 2 groups-HP (approximately 30% energy from protein, 40% from carbohydrate, and 30% from fat) or HC (approximately 55% energy from carbohydrate, 15% from protein, and 30% from fat)-for 4 weeks. They were provided all food and drinks in 3-day cycle menus for 28 days. Diets provided basal and ad libitum components. Physical activity level was monitored everyday by a pedometer. The pedometers were worn everyday aside from sleeping and bathing. Body weight was measured before and after the intervention. During the 4-week intervention period, the HP group's protein intake was significantly higher at 30.1% energy than that of the HC group at 15.1% energy (P < .001). The HP group's carbohydrate intake was 41.1% energy, and that of the HC group was 56.3% energy; they were significantly different (P < .001). Daily energy, lipid, and fiber intakes were similar among the 2 groups (1558 and 1551 kcal, 49.4 and 49.5 g, and 8.9 and 8.9 g, respectively). Changes in body weight during the intervention period were similar in the HP and HC groups, being 0.00 +/- 3.43 and 0.04 +/- 0.65 kg, respectively (P > .05). In healthy young Vietnamese women with a normal body mass index, those who consumed the HP and HC diets were similar in their energy intakes and changes in body weight, indicating that neither an HP nor an HC diet had any advantage or disadvantage in weight control in healthy young nondieting women.