A summary of the evidence of the effects of Alcohol on body weight

Smiling lady with glass of red wine

Does alcohol or wine cause you to put on weight?

Despite the calories in a glass of wine there is substantial clinical evidence that it does not cause the expected weight gain. The reason for this is unclear but animal studies have confirmed the theory that the body may process alcohol in a different way to certain foods meaning that excess calories are not automatically converted to fat. So headlines in the newspapers that a glass of wine contains the same calories as a slice of cake may be true, but the effect on the body is not the same as eating cake. 

The calorie was first defined by Nicolas Clément in 1824 as a unit of heat energy.The word comes from Latin calor meaning "heat" and is the approximate amount of energy needed to raise the temperature of one gram of water by one degree Celsius. Confusingly, the word calorie is very often used for what is actually a kilocalorie of nutritional energy. Sometimes, in an attempt to avoid confusion, it is written Calorie (with a capital "C") in an attempt to make the distinction, although this is not universal, and is not widely understood. So 1 Calorie  ≡ 1 kcal = 1000 cal.

The concept of Calories may be easy for nutritionists to explain to the obese but in the context of alcohol consumption further research is needed to explain the apparent anomalies. For example, sugar laden mixers in cocktails may be far worse for you than the alcohol itself. 

For Calorie and nutritional information by type of wine click below:

In 1991 Lieber CS in "Perspectives: do alcohol calories count?" wrote that "Chronic consumption of substantial amounts of alcohol is not associated with the expected effect on body weight. Isocaloric substitution of carbohydrates by ethanol results in weight loss, and addition of ethanol to an otherwise normal diet does not produce the expected weight gain. This energy deficit cannot be explained by maldigestion or malabsorption but has been attributed to induction of the microsomal ethanol oxidizing system (a metabolic pathway that oxidizes ethanol without associated chemical energy production), increased sympathetic tone and associated thermogenesis, and/or enhanced ATP breakdown (with increased purine catabolism) secondary to the acetate produced from ethanol. All these hypotheses do not fully explain the lack of weight deficit when alcohol is consumed with a very-low-fat diet, which suggests that an alteration in the energy utilization derived from fat plays a major role, possibly through uncoupling of oxidation with phosphorylation in mitochondria damaged by chronic ethanol consumption."

Liu S 1994 "A prospective study of alcohol intake and change in body weight among US adults", reported that "At baseline, women who reported at least one drink per day weighed 2.3 kg less than nondrinkers (95% confidence interval (CI) -0.4 to -4.2). Little relation was observed between body weight and alcohol intake cross-sectionally among men. Prospectively, both men and women drinkers tended to gain less weight than did nondrinkers (p = 0.006 for trend in women, p = 0.11 for trend in men). Drinkers also had more stable weight over the 10-year follow-up period. Drinkers were less likely to have majorweight gain or loss (gaining or losing > or = 10 kg) than were nondrinkers. Compared with nondrinkers, for those who consumed 1-6.9 drinks per week, women had an odds ratio (OR) = 0.7 (95% CI 0.5 to 0.9) for major weight gain and an OR = 0.7 (95% CI 0.5 to 1.1) for major weight loss, while men had an OR = 1.0 (95% CI 0.6 to 1.6) for major weight gain and an OR = 0.7 (95% CI 0.5 to 1.2) for major weight loss. For those who consumed > or = 2 drinks per day, women had an OR = 0.5 (95% CI 0.3 to 1.0) for major weight gain and an OR = 0.8 (95% CI 0.4 to 1.6) for major weight loss, while men had an OR = 0.9 (95% CI 0.5 to 1.6) for major weight gain and an OR = 1.0 (95% CI 0.6 to 1.7) for major weight loss. "

The authors concluded that "These data suggest that alcohol intake does not increase the risk of obesity."

Cordain L 1997, "Influence of moderate daily wine consumption on body weight regulation and metabolism in healthy free-living males" published that "Whether wine was imbibed or not, no significant differences (p > 0.05) were demonstrated for any of the following variables: body weight,body fat percentage, skinfold thickness, resting metabolic rate, respiratory quotient, caloric intake, dietary macronutrient content, or fasting insulin or glucose concentrations."

They concluded that "In free-living subjects over a 6-week period, the addition of two glasses of red wine to the evening meal does not appear to influence any measured variable which may adversely affect body weight or promote the development of obesity during this time period."

Wannamethee SG 2004 "Alcohol intake and 8-year weight gain in women: a prospective study" stated that "In cross-sectional analyses, there was a significant inverse relationship between alcohol and BMI even after adjustment for dietary factors and a wide range of confounders. In multivariate prospective analyses, a nonlinear relationship was seen between alcohol and weight gain (>or=5 kg) in all women. Compared with nondrinkers, the adjusted relative odds [95% confidence interval (CI)] of weight gain according to grams per day were 0.94 (0.89, 0.99) for those consuming 0.1 to 4.9 g/d, 0.92 (0.85,0.99) for 5 to 14.9 g/d, 0.86 (0.76, 0.78) for 15 to 29.9 g/d, and 1.07 (0.89,1.28) for those consuming 30+ g/d (p < 0.0001 for quadratic trend). Women who continued to drink heavily and those who became heavy drinkers showed similar increased odds of weight gain. The increased odds of weight gain associated with heavy drinking (30+ g/d) were most marked in the younger women (<35 years) (odds ratio 1.64; 5% CI 1.03 to 2.61). In African-American women, light drinking was associated with increased odds of weight gain compared with nondrinkers (odds ratio = 2.43; 95% CI 1.22 to 4.82)."

They concluded that "Our data suggest that light to moderate drinking (up to 30 g/d) is not associated with weight gain in women except possibly in African-American women. Heavier drinking may promote weight gain in women."

Tolstrup JS et al 2008  in "Alcohol drinking frequency in relation to subsequent changes in waist circumference" published that "Drinking frequency was inversely associated with changes in waist circumference in women and was unassociated with changes in waist circumference in men. Drinking frequency was unassociated with major waist loss but was inversely associated with major waist gain: odds ratios among men were 0.97 (95% CI: 0.73, 1.28), 0.95 (95% CI: 0.81, 1.12), 0.88 (95% CI: 0.77, 0.99), 0.82 (95% CI: 0.71, -0.95), and 0.79 (95% CI: 0.69, 0.9) for never drinking, drinking on 1, 2-4, 5-6, and 7 d/wk, respectively, compared with men who drank alcohol on <1 d/wk (P for trend < 0.0001). Results for women were similar. Adjustment for the amount of alcohol intake or total energy intake did not affect results considerably."

They concluded that "Drinking pattern may be associated with development of abdominal obesity; in this prospective study, drinking frequency was inversely associated with major waist gain and was unassociated with major waist loss."

In 2010 Wang et al in "Alcohol consumption, weight gain, and risk of becoming overweight in middle-aged and older women" reported that "There was an inverse association between amount of alcohol consumed at baseline and weight gained during 12.9 years of follow-up. A total of 7942 (41.3%) initially normal-weight women became overweight or obese (BMI > or =25) and 732 (3.8%) became obese (BMI > or =30). After adjusting for age, baseline BMI, smoking status, nonalcohol energy intake, physical activity level, and other lifestyle and dietary factors, the relative risks of becoming overweight or obese across total alcohol intake of 0, more than 0 to less than 5, 5 to less than 15, 15 to less than 30, and 30 g/d or more were 1.00, 0.96, 0.86, 0.70, and 0.73, respectively (P( )for trend( )<.001). The corresponding relative risks of becoming obese were 1.00, 0.75, 0.43, 0.39, and 0.29 (P( )for trend( )<.001). The associations were similar by subgroups of age, smoking status, physical activity level, and baseline BMI.

Wang concluded that "Compared with nondrinkers, initially normal-weight women who consumed a light to moderate amount of alcohol gained less weight and had a lower risk of becoming overweight and/or obese during 12.9 years of follow-up."