The Truth About HGH for Weight Loss
Can human growth hormone help you burn fat and build muscle?By Kathleen M. Zelman, MPH, RD, LDFROM THE WEBMD ARCHIVES
Can a naturally occurring hormone that promotes growth and development be a dieter’s dream come true? The quest for an easier weight loss solution has some people taking human growth hormone (HGH) in pills, powders, and injections.
A few small studies have linked HGH injections with fat loss and muscle gain. But the changes seen were minimal — just a few pounds — while the risks and potential side effects are not. And experts warn that HGH is not approved by the Food and Drug Administration (FDA) for weight loss.
How HGH Works
HGH is produced by the pituitary gland to fuel growth and development in children. It also maintains some bodily functions, like tissue repair, muscle growth, brain function, energy, and metabolism, throughout life.
HGH production peaks during the teenage years and slowly declines with age. Studies have shown that obese adults have lower levels than normal-weight adults. And these lower levels of HGH have some people wondering whether a boost of HGH could enhance weight loss, especially in the obese.
Growth hormone (GH) can induce an accelerated lipolysis. Impaired secretion of GH in obesity results in the consequent loss of the lipolytic effect of GH.
Dietary restriction as a basic treatment for obesity is complicated by poor compliance, protein catabolism, and slow rates or weight loss. GH has an anabolic effect by increasing insulin-like growth factor (IGF)-I.
We investigated the effects of GH treatment and dietary restriction on lipolytic and anabolic actions, as well as the consequent changes in insulin and GH secretion in obesity.
24 obese subjects (22 women and 2 men; 22-46 years old) were fed a diet of 25 kcal/kg ideal body weight (IBW) with 1.2 g protein/kg IBW daily and were treated with recombinant human GH (n = 12, 0.18 U/kg IBW/week) or placebo (n = 12, vehicle injection) in a 12-week randomized, double-blind and placebo-controlled trial.
GH treatment caused a 1.6-fold increase in the fraction of body weight lost as fat and a greater loss of visceral fat area than placebo treatment (35.3 vs. 28.5%, p < 0.05). In the placebo group, there was a loss in lean body mass (-2.62 +/- 1.51 kg) and a negative nitrogen balance (-4.52 +/- 3.51 g/day). By contrast, the GH group increased in lean body mass (1.13 +/- 1.04 kg) and had a positive nitrogen balance (1.81 +/- 2.06 g/day).
GH injections caused a 1.6-fold increase in IGF-I, despite caloric restriction. GH response to L-dopa stimulation was blunted in all subjects and it was increased after treatment in both groups.
GH treatment did not induce a further increase in insulin levels during an oral glucose tolerance test (OGTT) but significantly decreased free fatty acid (FFA) levels during OGTT. The decrease in FFA area under the curve during OGTT was positively correlated with visceral fat loss.
This study demonstrates that in obese subjects given a hypocaloric diet, GH accelerates body fat loss, exerts anabolic effects and improves GH secretion. These findings suggest a possible therapeutic role of low-dose GH with caloric restriction for obesity.