Can I speed up my metabolism?

Honest answer first: there is no food, supplement, or hack that meaningfully speeds up metabolism. Chili peppers, green tea, and metabolism-booster supplements nudge calorie burn by amounts too small to matter - a few calories, not a transformation. Anything promising more is marketing. What actually determines your burn: body size and muscle mass - bigger and more muscular bodies burn more at rest - age, since metabolism drifts down as muscle fades, sex, and genetics. Daily movement matters more than most people think: everyday non-exercise movement - walking, stairs, standing, fidgeting - can differ by hundreds of calories a day between people and is the most adjustable dial. So the real levers are boring but effective: build or keep muscle with resistance training two or more times a week, move more through the day, eat enough protein, sleep enough, and avoid crash diets - severe restriction slows metabolism and costs muscle, which is why weight regain after crash dieting is so common. The NIDDK Body Weight Planner shows what realistic intake changes do over time if you want the math. One medical note: if weight is climbing despite no lifestyle change, with fatigue and cold intolerance, get a thyroid test - a slow thyroid genuinely slows metabolism, and it is fixable. Pymander is a free AI doctor, 24/7 by text. It can help you build a realistic plan around your actual numbers.