Influence of chronic alcohol abuse on body weight and energy metabolism: is excess ethanol consumption a risk factor for obesity or malnutrition?

OBJECTIVES

To evaluate the influence of chronic alcohol abuse on body composition and energy metabolism in patients affected by chronic alcoholism (group A) compared with a group of healthy social drinkers (group B).

SETTING

A university hospital clinic in Italy.

SUBJECTS

A total of 32 alcoholics without clinical or laboratory signs of liver cirrhosis and malabsorption.

MEASUREMENTS

Body composition was assessed by anthropometric measurements. Resting energy expenditure (REE) and substrate oxidation rate was measured by indirect calorimetry. Daily caloric intake was computed on the basis of a food diary compiled over 7 days.

RESULTS

Alcoholics showed a significantly lower body weight (P < 0.05) and a significant lower fat mass (P < 0.05) compared with controls. A higher waist-to-hip ratio was found in group A than in group B, both as a whole group (P < 0.01) or separated by gender (females, P < 0.01) and males, P < 0.001), indicating a prevalence of fat distribution in the abdominal region in alcoholics. REE was significantly higher in group A than in group B (P < 0.05). The non-protein respiratory quotient was significantly lower in group A than in group B (P < 0.001) with a consequent higher utilization of lipids (P < 0.01) and a lower carbohydrate oxidation (P < 0.05) in group A. The energy intake provided only by food ingestion was found to be significantly higher in group B (P < 0.01), whilst the total caloric intake, computed as food intake plus alcohol intake, was higher in group A (P < 0.01).

CONCLUSIONS

Alcoholics, as compared with social drinkers, showed a lower body weight due essentially to a fat mass reduction, a higher REE value normalized by fat-free mass, and a preferential utilization of lipids as energy substrate. These findings might suggest that chronic ethanol abuse is able to determine an impairment of nutritional status due, at least in part, to an alteration of the substrate oxidation.