[Hypocaloric and high-protein diet in obese patients: changes in the lean mass]

We have followed for 40 days seven hospitalized, young (age, mean SD : 33 +/- 8 yrs), and moderately obese (W/H : 35 +/- 3.92) women. During the first 5 days (DO to D5) they received a diet similar to their customary home-diet; from D6 to D40, their daily caloric intake was adjusted to 3,41 +/- 0.13 MJ (816 +/- 30 kcal). This diet comprised 21 p. 100 of sugars, 35 p. 100 of lipids, 1.57 +/- 0.09 g proteins per kg ideal body weight. Five seven-day periods have been studied. On the first day of each period, we recorded body weight and measured plasma albumin, pre albumin, retinol binding protein, complement (CH50 and C3) C peptide (in the fasting state and after glucagon stimulation), and thyroid hormones (T3 and rT3). On each of the 35 days of this study, total nitrogen was measured (Kjeldahl's method) in food, urine and faeces. On D0 and D41 lean and fat body masses were evaluated through measurements of total water (dilution of tritiated water) and of skin fold thickness respectively. From D0 to D40, the average weight loss was 8.76 +/- 1.86 kg; the cumulated nitrogen balances were negative in 6 patients and positive in one, with variations from one period to another and from one patient to another. Plasma proteins and hormones did not vary significantly. Changes in lean mass were comprised between + 0,7 and -- 1,6 kg in spite of the fact that all patients received the same caloric and protein intake.