Several common drinks can temporarily increase your metabolic rate, with green tea, coffee, cold water, and high-protein beverages having the strongest evidence behind them. The effects are real but modest, typically ranging from a 3–12% bump in energy expenditure that lasts a few hours. Here’s what each drink actually does and how much of a difference you can realistically expect.
Green Tea
Green tea is one of the most studied metabolism-boosting drinks, and it delivers results that go beyond its caffeine content alone. In controlled trials, green tea extract increased 24-hour energy expenditure by about 4% compared to a placebo. More telling, it outperformed caffeine-only treatments by 2.8%, meaning something else in the tea is pulling extra weight. That something is a group of plant compounds called catechins, which work alongside caffeine to stimulate your body’s heat production and fat burning.
The practical difference is small but measurable. A 4% increase in daily energy expenditure translates to roughly 60–100 extra calories burned over 24 hours, depending on your size and activity level. Green tea also shifted the body’s fuel preference toward fat: subjects burned a higher proportion of fat relative to carbohydrates while the tea was active. To get a meaningful dose of catechins, you’d need about 3–4 cups of brewed green tea per day.
Coffee and Caffeine
Coffee’s metabolic boost comes primarily from caffeine, which increases both your resting energy expenditure and the caloric cost of physical activity. During light exercise, caffeine raised the number of calories burned by about 8% on average, with the effect growing slightly over a 30-minute period. Even at rest, caffeine elevated energy expenditure noticeably in the minutes before activity began.
There’s an important caveat: your body develops tolerance. Regular caffeine consumption reduces the metabolic and performance benefits of each cup, though it doesn’t eliminate them entirely. Research shows this tolerance sets in within the first month of daily use and then stabilizes, so habitual coffee drinkers still get a boost, just a smaller one than occasional drinkers. The FDA considers up to 400 milligrams of caffeine per day safe for most adults, which works out to roughly two to three standard 12-ounce cups of coffee.
Cold Water
Plain water might be the most underrated option on this list. Drinking 500 ml (about 17 ounces) of water increased metabolic rate by 30% in one well-known study, generating roughly 24 extra calories of heat. About 40% of that effect came from the simple physics of warming cold water to body temperature. The rest was driven by your nervous system ramping up energy expenditure in response to the fluid intake.
Twenty-four calories per glass isn’t dramatic, but water is calorie-free, and the effect stacks across a full day of adequate hydration. If you drink six to eight glasses, the cumulative thermogenic effect becomes meaningful, especially compared to replacing water with sugary beverages that add calories without any metabolic advantage.
Oolong Tea
Oolong tea sits between green and black tea in terms of oxidation, and it has its own metabolic profile worth noting. In a study comparing full-strength oolong tea to plain water, the tea increased energy expenditure by about 2.9%. Fat oxidation, the rate at which your body breaks down stored fat for fuel, jumped by 12%. That fat-burning bump was unique to the whole tea, not just the caffeine in it, suggesting oolong’s specific blend of polyphenols plays a role.
If you find green tea too grassy or bitter, oolong offers a similar metabolic benefit with a smoother, more complex flavor. It contains moderate caffeine, typically 30–50 mg per cup, so it’s also a reasonable option later in the day when a full cup of coffee might interfere with sleep.
Protein Shakes and Smoothies
Your body uses energy to digest and process food, a phenomenon called the thermic effect of food. Protein demands far more processing energy than other nutrients: 20–30% of the calories in protein are burned just digesting it, compared to 5–10% for carbohydrates and 0–3% for fat. A protein shake with 30 grams of protein costs your body roughly 25–35 calories just to absorb, whereas the same calorie amount from pure fat would cost almost nothing.
This makes protein-rich drinks like whey shakes, casein smoothies, or even high-protein milk effective metabolic tools, particularly after exercise or as meal replacements. The boost isn’t from a magic ingredient but from the basic chemistry of protein digestion, which requires more steps and more energy than breaking down fats or carbs.
Ginger Tea and Spiced Drinks
Hot ginger tea increases the thermic effect of a meal by a meaningful margin. In a study of overweight men, dissolving ginger powder in hot water alongside a standard breakfast increased calorie burn by about 43 calories over six hours compared to hot water alone. Ginger activates the same receptor channels that capsaicin (the compound in chili peppers) triggers, producing a warming sensation that kicks your sympathetic nervous system into a slightly higher gear.
Spicy drinks work through a similar mechanism. Meals containing chili and mustard raised metabolic rate by 25% more than the same meal without spices. Beyond the thermogenic effect, ginger also promoted feelings of fullness, which could reduce overall calorie intake. A simple ginger tea made from fresh or powdered ginger is enough to trigger this response.
What These Numbers Actually Mean
It’s worth being honest about scale. The metabolic bumps from these drinks range from about 24 extra calories (a glass of cold water) to roughly 80–100 calories over a full day (several cups of green tea). No drink will compensate for a significant calorie surplus or replace exercise. Where these drinks become genuinely useful is in the margins: choosing green tea over a sugary latte, drinking cold water instead of nothing, or adding protein to a smoothie instead of just fruit. Those small shifts, repeated daily, compound over weeks and months.
Combining strategies amplifies the effect. A morning coffee, a protein-rich smoothie at lunch, green or oolong tea in the afternoon, and consistent water intake throughout the day could realistically add 150–200 extra calories of expenditure, roughly equivalent to a 20-minute walk. None of these drinks are shortcuts, but they’re low-effort additions that nudge your metabolism in the right direction while offering other health benefits along the way.