A reduction in Basal Metabolic Rate (BMR) of up to 15% can occur beyond what is expected from tissue loss alone, due to metabolic adaptation.

“so choosing that percentage rate of loss is important why it's important is because we when we see extreme dietory interventions carried out continuous diet interventions that push weight loss Beyond those numbers we are increasing the risk of metabolic adaptation so now we're starting to look at um you know more um I guess adaptive mechanisms a greater response to um dieting or our self-defense system really really you know ramps up um we become far more efficient so we want to keep the rate at that that level and that will help to keep your BMR your basil metabolic rate nice and high and it's protective of your muscle mass”