Obesity and cardiovascular risk.

In this paper the general concepts of the relationship between body weight, food intake and susceptibility to vascular disease are re-examined in the light of recent evidence. Several studies suggest that the traditional view of the relationship between mortality and adiposity as direct and linear are mistaken and that the relationship is 'U' shaped with minimal mortality at 'average' rather than 'ideal' weight. Furthermore, the notion that higher levels of food energy intake may be responsible for the enhanced susceptibility to arterial disease are also challenged by those in the lower than the upper ranges of total caloric intake. This may account for some of the anomalous inverse relationships found within countries between food (including fat) intake and arterial disease deaths, findings which have stood for years in irreconcilable contrast with the direct relationship between fat intake and cardiovascular mortality between countries. These apparently paradoxical relationships may be explained by the further unexpected finding of low order but highly significant inverse correlations between food energy intake and adiposity. This has supported the notion of a spectrum of energy conservation/dissipation with the energy conserver storing fat even on low intakes and the dissipator expending a high intake yet remaining lean. Adaptive responses to excess intake and to food deprivation may also be involved in this constitutional variation in energy handling.