An experiment was conducted in the semi-arid temperate highlands of central Mexico (1994–95) with 12 adult, female non-pregnant, non-lactating, crossbred Nubian goats to determine the effects of 36 weeks of feed restriction on body weight, carcass composition and blood concentrations of glucose and hormones (insulin, triiodothyronine [T₃] and tetraiodothyronine [T₄]). After a 9-week feed intake, liveweight and body condition stabilization period, the animals were divided into three groups and individually offered either 100, 80 or 60% of their observed average daily consumption. Feed intake was measured daily, liveweight weekly, and blood-serum glucose and hormone concentrations every 4 weeks. At the end of the feeding experiment, the animals were slaughtered, and the carcasses and viscerae weighed. Liver and muscle samples were obtained and chemically analysed. Insulin and T₄ did not differ between treatments (P>0·05). Final liveweight; blood-serum glucose and T₃; carcass yield; muscle tissue dry matter, fat, RNA and RNA:protein ratios; hepatic tissue protein, RNA:DNA and protein:DNA ratios decreased, while liver and muscle DNA increased with restriction (P<0·05). These results suggest that capacity of goats to adapt to long term undernutrition and the importance of hepatic and muscle tissues as sources of metabolic energy.