On average, one serving of alcohol contains 100–150 calories, so even a moderate amount of 3 drinks a day can contribute around 300+ calories to your calorie budget. Mixed drinks that add juice, tonic, or syrups will further drive up calories, increasing the risk of weight gain over time.
Alcohol can suppress the anti-diuretic hormone, a fluid-regulating hormone that signals the kidneys to reduce urination and reabsorb water back into the body. Without it, the body flushes out water more easily.
Enjoying more than a couple of drinks within a short time can increase dehydration risk, especially if taken on an empty stomach. To prevent this, take alcohol with food and sips of water.
If you don't drink, there's no need to start. If you already drink alcohol or plan to begin, keep it moderate—no more than 2 drinks a day for men or 1 drink a day for women. Make sure you get adequate amounts of folate, at least 400 micrograms a day.