[Membrane fluidity and obesity: the correct food approach]

Modifications in dietary fat profile have shown to affect body weight gain and adiposity. This may occur through the changes of cell membrane fluidity, in particular of the peripheral muscle tissue. The decreased availability of diet polyunsaturated fatty acids (in particular of the to-3 series), that are able to induce membrane fluidification, together with an excessive intake of both saturated fatty acids and cholesterol, that on the contrary are able to rigidify the same membranes, promoter both a progressive immobilization of membrane proteins and a consequent decrease in their functional rate of liver lipoproteins VLDL, enriched in saturated fats and cholesterol. This lipoprotein increase promotes both the fat deposition in the adipose tissues and a further increase in the muscle membrane rigidity that is followed by a further enhancement in the peripheral resistance to insulin. A diert rich both in polyunsaturated fatty acids and antioxidants (vitamin and oligoelements), and in essential amino acids together with a preferential choice of complex carbohydrates (amylose, amylopectine, etc) in comparison to simple sugars (glucose, fructose, saccharose, lactose, etc) may significantly contribute to the maintenance of the correct degree of membrane fluidity and, as a consequence, to the physiologically correct body weight.