Anyone suffering from pandemic pounds? Recent shutdowns have impacted physical activity for many of us, and the holiday season is approaching. But for those who worry that their glass of wine with dinner is contributing to the calories, researchers in the U.K. have published a new study analyzing the relationship between obesity and alcohol that will be encouraging to moderate wine drinkers. According to the data, people who drink moderately have lower body mass indexes (BMI) than people who avoid alcohol. What's more, the type of alcohol consumed played a key role.
Published this summer in the International Journal of Environmental Research and Public Health, the study investigates the relationship between alcohol consumption and body mass index, as well as how different types of alcohol impact obesity rates. Researchers from Australia and the U.K. teamed up and analyzed data amassed over four years from more than 280,000 participants as part of the U.K. Biobank Resource. The age range of the participants was 40 to 69 years and they were recruited from throughout the U.K.
Study participants had their height and weight measured regularly and reported their level of drinking based on units of alcohol (one unit being 10 milliliters of pure alcohol, which is roughly equal to one glass of wine). Researchers classified participants into five levels of alcohol consumption: those who never drink; those who drank in the past; "moderate" drinkers (less than 14 drinks per week for women and less than 21 drinks for men); "hazardous" drinkers (between 14 to 34 drinks per week for women and 21 to 48 for men); and "harmful" (more than 35 drinks per week for women and more than 49 for men). They also tracked participants' physical activity, diet, socioeconomic status and whether they smoked.
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The study found that the participants in both the "moderate" and "hazardous" drinking categories had lower BMIs than those who never drank. Moderate drinkers had the lowest BMIs. The researchers ran several analyses and in models that adjusted for participants' education levels these effects persisted. Even those classified as harmful drinkers showed lower BMIs than those abstaining from alcohol altogether. Participants in the moderate and hazardous drinking groups also had the lowest levels of obesity.
The researchers also found that the lower BMIs for moderate drinkers were due to a specific type of drinker in this cohort: wine drinkers. Wine drinkers had lower BMIs than both abstainers and those who consumed beer and spirits. In fact, people who consumed beer and spirits had higher BMIs than the abstainers. Out of all the groups, wine drinkers also reported the lowest obesity levels.
The researchers have several theories as to why they saw an inverse relationship between alcohol consumption and BMI: alcohol may affect an individual's energy balance, may increase insulin sensitivity and reduce body-fat storage, and the metabolizing of alcohol may burn extra calories. The researchers also say it's possible that other factors, such as income levels and lifestyle habits of moderate drinkers, play a role. Previous studies have shown that moderate drinkers may belong to higher socio-economic groups, which tend to have different exercise and dietary habits.
The researchers caution that the harmful health effects of the amount of alcohol consumed by the highest drinking groups must be taken into consideration. Heavy drinking and binge drinking put individuals at risk for various other health issues. Alcohol is not a diet product and should not be used as such. People should consult their physician to determine the best diet for them.
Further studies are needed to investigate the link between alcohol consumption and BMI, and why a glass of wine with dinner may not be the calorie concern we thought it was.