One of the keys to successful weight loss is avoidance of excessive hunger. Hunger is a powerful driver of feeding behaviour, perhaps second only to that of the desire to drink, and while in the short term hunger signals can be overcome, eventually even those with the strongest determination will succumb to a ravenous appetite. The main problem with an out of control appetite is that it increases the risk of eating low quality foods that are energy dense and contain refined and processed foods. Energy restrictive diets increase the strength of the hunger signal over time and this is one of the reasons they are not successful in the long term. As the diet progresses, generally the hunger signal increases because the hypothalamus receives signals that are interpreted as an energy deficit and it then makes hormonal corrections to allow for increased energy intake. One of the hormones that is involved with stimulating appetite is ghrelin, which can be thought of as the hunger hormone.
Studies investigating changes to satiety and appetite hormones over the course of energy restrictive diets have been performed. For example in one study1, researchers measured the changes to a number of known satiety and hunger signals in subjects during the course of a 10 week energy restricted weight loss regime, and also during a follow-up assessment after one year. The results of the study showed that as the 10 week diet progressed the circulating levels of ghrelin, a hormone that has been shown to be associated with hunger, increased significantly. Over the course of the next year the ghrelin levels dropped during the maintenance phase of the diet, but by one year they had not returned to baseline. The relatively higher levels of ghrelin in the blood were accompanied by increased feelings of hunger in the subjects. The increase in hunger throughout the maintenance phase may explain why the subjects regained much of the lost weight within the one year period of the follow up.
RdB
