Latin for "at one's pleasure" or "as you desire." In biology, this term is used to describe "free feeding."

A type of protein that acts on neurons in the central and peripheral nervous systems. BDNF is a type of neurotrophin – or growth factor – that controls and promotes the growth of new neurons. It is active in the hippocampus, cortex, cerebellum, and basal forebrain – areas involved in learning, long term memory, and executive function. Rodent studies suggest that lactate, one of many so-called exerkines, mediates some of the benefits of exercise on learning and memory via inducing neuronal BDNF expression.^[1] Exercise in combination with heat stress increases BDNF more effectively than exercise alone.^[2] BDNF is a profoundly universal point of convergence for mechanistically explaining essentially all known activities that promote brain health.

A hormone produced primarily by adipocytes (fat cells) that signals a feeling of satiety, or fullness, after a meal. Leptin acts on cells in the hypothalamus to reduce appetite and subsequent food intake. Leptin’s effects are opposed by ghrelin, the “hunger hormone.” Both acute and chronic sleep deprivation decrease leptin levels.

A metabolic disorder characterized by high blood sugar and insulin resistance. Type 2 diabetes is a progressive condition and is typically associated with overweight and low physical activity. Common symptoms include increased thirst, frequent urination, unexplained weight loss, increased hunger, fatigue, and impaired healing. Long-term complications from poorly controlled type 2 diabetes include heart disease, stroke, diabetic retinopathy (and subsequent blindness), kidney failure, and diminished peripheral blood flow which may lead to amputations.