Fig 2. Association of caffeine intake with erectile dysfunction among normal weight and overweight/obese men in NHANES 2001–2004.

^†Adjusted for age, vigorous and moderate physical activity, smoking status, education, race/ethnicity, obesity (BMI ≥ 30 kg/m²), total water intake (plain and tap), total energy (continuous), alcohol (continuous). Error bars represent 95% confidence intervals. P _trend = 0.08 and P _interaction = 0.09. ^*Erectile dysfunction was defined as “sometimes” or “never” able to maintain an erection for satisfactory sexual intercourse. ^‡ Approximately 170–375 mg/day of caffeine intake is equivalent to 2–3 cups of coffee. ^aOverweight/obesity = body mass index ≥ 25 kg/m².