Wine, like all foods, can benefit us in some ways. Many studies studies (paywall) have shown that in small to moderate amounts, wine may reduce risks for some kinds of heart disease.
However, the evidence that drinking wine before bed can help you lose weight is murkier. Most of the news stories I found referenced a 2015 study conducted by researchers at Washington State University, which found mice whose diets were enhanced with just a little bit of resveratrol—a compound produced in plants—developed a little more beige fat, which is made of smaller cells that burn energy to keep our bodies warm, instead of white fat, which is made of larger cells that store energy and expand as we gain weight.
You can get resveratrol from drinking wine—but not very much. It’s much easier to get this chemical from about three servings of raw fruit. Additionally, this study looked at the chemical’s effect in mice. Although mouse models can be very good at approximating what may happen in people, this isn’t always the case. Studies done on animals instead of humans aren’t necessarily bad, but need to be taken with a grain of salt when they’re extrapolated up to people.
There were also references to a Harvard study of 20,000 women over 13 years that showed that those who were drinking wine had a “70% reduced risk of obesity.” (As Snopes points out, this study is never linked to in most of these news stories.) The Harvard study they seem to be referring to is from 2010, published in JAMA Internal Medicine. Researchers found that light drinking initially slowed weight gain in women, although these women self-reported their weight over time. Some women who drank actually gained weight. Even if the alcohol consumption here was linked to weight loss, it doesn’t necessarily mean that there is a causal relationship.
Finally, there’s only weak evidence that drinking wine at night will help curb your late-night appetite. One study, conducted on bees, found that the insects did eat less (and live longer) when they were fed diets supplemented with resveratrol. But it’s even more difficult to extrapolate these results to humans.
In general, alcohol actually disrupts (paywall) sleep, which can affect our hormonal balance and lead us to eating more.