Among overweight and obese patients with type 2 diabetes, “abstaining from alcohol offers some modest benefits for long-term weight control,” researchers report, in a new study published online in the journal Obesity.

Specifically, in the intensive lifestyle intervention arm of the Action for Health in Diabetes (Look AHEAD) study of overweight or obese patients with type 2 diabetes, those who drank alcohol or abstained had a similar weight loss at 1 year, but by 4 years the weight loss was less sustained in those who drank alcohol.

This study indicates that in obese or overweight individuals with type 2 diabetes, “while alcohol consumption is not associated with [worse] short‐term weight loss during a lifestyle intervention, it is associated with worse long‐term weight loss,” lead investigator Ariana M. Chao, PhD, CRNP, assistant professor of nursing, University of Pennsylvania School of Nursing, Philadelphia, said in a statement by her university.

Thus, “patients with type 2 diabetes who are trying to lose weight should be encouraged to limit alcohol consumption,” according to Chao.

“Decreasing alcohol consumption may improve weight management among individuals with diabetes,” she and her colleagues conclude in their article.

However, they also concede that the clinical significance of their findings “is uncertain, and results should be taken in context of the potential (though controversial) benefits of light to moderate alcohol consumption.”

That is, other researchers have reported a “J-” or “U-shaped” relationship between alcohol consumption and cardiovascular disease (where being a light or moderate alcohol drinker confers benefit), but on the other hand, drinking any amount of alcohol has been linked with an increased risk of breast cancer.

Chao and colleagues suggest that in their study “participants who drank alcohol may have compensated for calories from alcohol during the short term (ie, by decreasing their calorie intake from food) but had more difficulties in the long term when weight typically plateaus and biological and behavioral factors may make it more difficult to maintain weight loss.”

More research is needed to examine how reducing or eliminating alcohol consumption affects long-term weight, they add, and to investigate “mediators underlying the effects of alcohol on weight-loss efforts, such as impulsivity, food choices, and physical activity.”

109 Calories a Day From Alcohol

Based on self-reports, more than 70% of Americans drink alcohol, and on average, Americans ingest 109 calories a day from alcohol, the researchers report.

Most weight-loss programs recommend cutting down on alcohol consumption, or abstaining altogether, to reduce calories, but the impact of alcohol intake on weight loss is not well understood.

To investigate this, Chao and colleagues examined accessible data from the 4901 participants in Look AHEAD from across the United States who were not Native Americans.

Of these, 2448 participants had been randomized to the intensive lifestyle intervention group and had received frequent individual and group counseling about diet and physical activity.

This included information that alcohol contains 7.1 calories/gram, and a standard drink of a 12-ounce beer (5% alcohol) or a 5-ounce glass of wine (12% alcohol) or 1.5 ounces of hard liquor (40% alcohol) each contains 0.6 fluid ounces or 14 grams of alcohol, which translates into, for example, 157 calories from a glass of wine, according to an NIH calculator.

Participants in this group were also informed that guidelines recommend no more than 2 drinks/day for men and 1 drink/day for women, and they were advised to reduce their alcohol consumption to cut calories.

The other 2453 participants in the diabetes support and education (control) group received three group counseling sessions a year about diet, exercise, and social support.

Based on the National Institute on Alcohol Abuse and Alcoholism’s drinking categories, all of the participants were classed as:

• Nondrinkers: No drinking at baseline.
• Light drinkers: < 7 drinks/week for men and < 4 drinks/week for women.
• Moderate drinkers: 7-14 drinks/week for men and 4-7 drinks/week for women.
• Heavy drinkers: > 14 drinks/week for men and > 7 drinks/week for women.

At baseline, about half of the cohort (54%) reported being light drinkers, and the rest were abstainers (38%) with few moderate drinkers (6%) or heavy drinkers (82 participants, 1.7%).

The participants were on average 60 years old and had a mean body mass index (BMI) of 35 kg/m² and had had diabetes for close to 7 years. About half were women.

In the intensive lifestyle intervention group, heavy drinkers, and abstainers had a similar mean weight loss at 1 year: 9.1% vs 8.9% of their initial weight, respectively (P = .99).

However, at 4 years, consistent teetotalers in the intervention group had lost 5.1% of their initial weight, whereas consistent heavy drinkers had only lost 2.4% of their initial weight (P = .04).

In the control group, abstainers and alcohol drinkers also lost similar (but much lower) amounts of weight at 1 year: 0.5% vs 0.7% of their initial weight, respectively (P = .60).

However, in this group, abstainers and alcohol drinkers also lost a similar amount of weight at 4 years (about 1.5% of their initial weight, P = .48).

A study limitation is the low number of participants who reported heavy alcohol consumption, Chao and colleagues acknowledge.

“Ultimately, randomized controlled trials are necessary,” they conclude, “to test whether eliminating alcohol consumption improves weight loss and other cardiovascular outcomes during lifestyle interventions.”