Body Composition
Definition
How body weight divides between fat mass and fat-free mass. Two interventions can produce the same change in total weight with very different composition behind it, which is why studies increasingly report the split rather than the total alone.
Where this term comes up
Entries whose definition mentions Body Composition.
What this means for research sourcing
Mechanistic terms like this describe how research compounds behave in vitro. See the mechanism overviews for compounds Volta stocks.
Related Terms in Pharmacology
Lean Body Mass
Everything in the body that is not fat: muscle, bone, organs and water. Studies report it beside total weight because a substantial reduction in body weight from any cause takes some of it along.
Visceral Adipose Tissue (VAT)
Fat held deep in the abdomen around the organs, as distinct from the layer directly under the skin. It is quantified by imaging rather than by a tape measure, and it is the endpoint the tesamorelin trials were built on.
Lipolysis
The breakdown of stored triglyceride into free fatty acids and glycerol. It is the measured endpoint behind a good deal of metabolic peptide work, including studies of HGH fragment 176-191 and AOD-9604.
Energy Expenditure
Total energy used over a day, made up of resting metabolism, the thermic effect of food and physical activity. Glucagon-receptor activity is one of the few peptide mechanisms proposed in trials to raise it directly rather than by reducing intake.
Insulin Resistance
A state in which muscle, liver and fat respond poorly to insulin, so more of it is needed to keep glucose in range. It is the physiological backdrop to most metabolic endpoints reported in this field.
Insulin Sensitivity
The converse measure: how strongly tissues respond to a given amount of insulin. Clamp studies are the reference method and surrogate indices derived from fasting bloods are what most papers actually report.
Angiogenesis
The growth of new blood vessels from vessels that already exist. It is central to tissue repair and is the mechanism most often proposed for the healing peptides, almost entirely on the strength of animal models.
Nitric Oxide
A short-lived gaseous signalling molecule that relaxes vascular smooth muscle and widens vessels. It is a separate pathway from melanocortin signalling, a distinction that gets blurred in writing about peptides with vascular effects.