Caloric versus low-caloric sweeteners: Can the body be fooled?

Low-caloric artificial sweeteners have been around for several decades now. Still, the debate over their usefulness in decreasing energy intake is ongoing. In principle, replacing sugar-containing foods with 'light' versions will lead to decreased energy intake. However, the reality of food intake behavior is not so simple and still many people tend to consume more calories than they burn and gain weight. Thus, 'light' products are not the easy solution they seem to be. Food intake regulation takes place in the brain. There, multiple neural and hormonal signals are integrated, ultimately leading to a particular pattern of food intake. For many years, the brain has been treated as a 'black box' in food research and other behavioral research alike. In recent years, however, functional neuroimaging techniques have enabled researchers to examine, noninvasively, the effects of different food stimuli in the human brain. This review summarizes literature on the effects of caloric and low-caloric sweeteners on physiological responses and eating behavior and specifically addresses recent neuroimaging studies. Such studies, along with others, suggest that the body cannot simply be 'fooled' by providing sweet taste without calories. Prevention of excess energy intake may not only be aided by refraining from liquid calories and other energy-dense 'fast foods', but also by a consistent relation between sweetness and caloric content. More research addressing the short as well as the long term effects of the replacement of foods and drinks by (partially) artificially sweetened 'light' versions is warranted.