Fig. 2

Fasting insulin levels compared with EC50 values for lipolysis inhibition, glucose uptake induction or gluconeogenesis inhibition. Fasting insulin data are taken from the National Health and Nutrition Examination Survey (NHANES) 1986–1994 [71]. Numbers in rectangular boxes indicate mean insulin concentration for 50% effect (EC50) on the stimulation of peripheral glucose uptake, as determined in different studies of non-obese adults. Mean insulin EC50 values for lipolysis inhibition were taken from [63, 64, 66,67,68,69, 113]; mean EC50 values for the stimulation of glucose uptake were taken from [64, 65, 67, 74, 75]; and mean EC50 values for the inhibition of gluconeogenesis were taken from [63,64,65, 67, 74]