Pathways to Obesity and Main Roads to Recovery

The chapter reviews the options for the currently available - or under study - antiobesity drugs, including those which have been removed from the market, being considered unsafe. The efficacy of different kinds of products is evaluated. Short term weight loss with drug treatment seems to be generally modest while maintenance in the long term is even more disappointing. Furthermore drug treatment cannot be prescribed without an associated reduction in energy intake, increased physical activity and lifestyle changes, otherwise weight loss will not be achieved and weight regain will annihilate the treatment effects. Drugs have shown wide ranging side effects and contraindication from a prolongued use. Orlistat, which reduces the absorption of fat from the gastrointestinal tract by lipase inhibition, is the most used drug in the present day context, while sibutramine or the endocannabinoids are not more available in most countries. Newer concepts in weight management are mainly hormonal and receptor based, in the effort to reduce adverse effects. Weight loss drugs in development, many of which are in phase II/III trials, include compounds which act at the central level to limit food intake such as neuropeptide Y, Agouty related protein, MCH1 receptor or Serotonin (5-HT) Receptor Ligands. Other compounds act as Gut Hormone Signaling, including Amylin Analogues or Cholecystokinin-1 or as (CCK) Agonists. Drugs such as metformin, topiramate, bupropion or naltrexone alone or as combination therapy are also used. Some pharmacological agents try to induce weight reduction by increasing energy expenditure or by reducing or redistributing adipose tissue