Coffee is one of the world’s favorite pick-me-ups, and in moderate amounts it can have real benefits. But some everyday habits around how, when and what you drink with your coffee can undercut those gains — or even cause harm. Below I rewrite and expand the original list into a practical, evidence-backed guide (with reputable sources cited). Tạp Chí Đời Sống

1) Drinking coffee on an empty stomach
Many people gulp a black coffee first thing. For some that’s fine, but coffee stimulates gastric acid and can aggravate heartburn or reflux in sensitive people — and it may make some stomach symptoms worse if you already have gastritis or GERD. If you notice burning, nausea or indigestion after a morning coffee, try eating a small snack first (yoghurt, a banana or a piece of toast) or choose a gentler brew. Harvard Health+1

2) Overdoing it: too much caffeine in a single day
Most health authorities say up to about 400 mg of caffeine per day appears safe for most healthy adults — roughly four cups of brewed coffee — but individual tolerance varies and certain groups (pregnant people, those with heart conditions, people on stimulants) should aim lower. High doses can cause anxiety, palpitations and even serious cardiac problems at extreme levels. Track your total caffeine from coffee, tea, energy drinks and meds. Mayo Clinic+1

3) Loading coffee with sugar, syrups or heavy creamers
Flavoured and sugary coffee drinks can hide a lot of added sugar and calories; frequent consumption of sugar-sweetened beverages is linked to weight gain and higher risk of type-2 diabetes and other metabolic harms. If you love a sweeter cup, reduce syrup pumps, swap in a dash of cinnamon or a small amount of milk, or choose unsweetened plant milks. CDC+1

4) Sipping coffee too late in the day
Caffeine’s effects last longer than many expect. Studies show caffeine taken even 6 hours before bedtime can significantly worsen sleep quality, so an afternoon cutoff — often around 2–3 p.m. for people who sleep at night — is a sensible rule of thumb if you have trouble falling or staying asleep. Remember individual metabolism varies: some people are more sensitive and need an earlier cutoff. PMC+1

5) Using very dark, burnt or low-quality beans without thinking about contaminants
Very dark roasts and some high-temperature cooking processes produce acrylamide, a processing contaminant that has raised safety questions in animal studies (food-science groups and regulators advise limiting exposure). That doesn’t mean you must quit coffee — population studies often find neutral or protective effects of habitual coffee — but prefer reputable beans, avoid aggressively burnt roasts, and don’t over-char your home roasts. The FDA and cancer-research bodies recommend practical ways to reduce acrylamide exposure when possible. U.S. Food and Drug Administration+2cancer.gov+2