title: Metabolic insufficiency as a limiting factor in the dietetic treatment of obesity.
abstract: Previous observations that acute total fasting decreases serum T3 and increase rT3 has prompted the following study. 17 obese women were placed on a 1000 kcal/day weight-reducing diet, and body weight (BW), serum T4, RT3U, T3, rT3, TSH and the Achilles tendon reflex (ATR) were estimated before and after each month for 3 consecutive months of the diet. The results showed a consistent decrease in serum T3, and inconsistent increase in rT3, a consistent prolongation of the ATR and a levelling-off of the BW loss after the second month of the diet. At 3 months there was a negative correlation between the decrease in BW and the increase in ATR, i.e. the more abnormal the ATR became, the less weight the patient lost. It is concluded: 1) Even a moderate hypocaloric diet in ambulatory patients induces a disturbance in the peripheral conversion of T4 to T3 and a secondary state of metabolic insufficiency. 2). This insufficiency is probable related to the observed tendency of the BW loss to level off after two months. 3) A controlled trial of physiologic doses of T3, such as 40 mu g/day, seems indicated, as opposed to pharmacologic dosed of T3 used by previous investigators.
mesh_terms: D000125:Achilles Tendon / Q000502:physiology; D000293:Adolescent; D000328:Adult; D001835:Body Weight; D005260:Female; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy* / Q000503:physiopathology; D012026:Reflex, Stretch; D014284:Triiodothyronine / Q000097:blood*; D014285:Triiodothyronine, Reverse / Q000097:blood*
chemical_list: D014284:Triiodothyronine; D014285:Triiodothyronine, Reverse