Maternal low-protein diet is associated with an age-related phenotypein rats, characterised by a period of resistance to development of obesity in earlyadulthood, giving way to an obesity-prone, insulin-resistant state in later adulthood.Offspring of rats fed a control (18 % casein) or low-protein (9 % casein; LP) diet inpregnancy were challenged with a high-fat diet at 9 months of age. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.