Provided herein are compositions (e.g., pharmaceutical compositions, nutraceutical compositions, foods, beverages, cosmetic compositions, diet supplements) comprising deuterated caffeine. The provided compositions may be useful for treating and/or preventing various diseases and conditions, such as obesity, causing weight loss, increasing metabolic rate, reducing appetite, increasing energy expenditure, increasing urine output, increasing sodium excretion, reducing edema, a pain disorder, apnea, hypotension, an encephalopathy, a neurological or psychiatric disorder, and an inflammatory disorder.