• Assessment
    In adult men, what is the acute effect of administration or changes in chemical use of caffeine on resting metabolic rate?
    • Conclusion

      Over 1½ to 3 hours after ingesting 200-350 mg caffeine, on average, RMR increased 4-11% above baseline in 38 healthy, non-obese men (18-65 years) that had mild to moderate daily caffeine consumption (90-200 mg caffeine/d).(Arcerio, 1995; Collins, 1994, and Koot, 1995).

    • Grade: II
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    In adult women, what is the acute effect of administration or changes in chemical use of caffeine on resting metabolic rate?
    • Conclusion

      In 10 lean women ((BMI 19.8±0.9 kg/m2(SD); 40-45 y) residing in Japan with daily mild to moderate coffee- or tea-drinking (50-200 mg caffeine/d), individual 30-minute post-caffeine ingestion (200 mg) RMR increases ranged from 10-23% above baseline (Yoshida, 1994). In age-matched, obese (BMI 30.9±1.5 kg/m2 (SD) women, a 30-minute post-caffeine ingestion RMR increase above baseline ranged from 1-25%. Correspondingly, group mean RMR increases were 15% and 14% in lean and obese Japanese women, respectively. In U.S.-residing moderate coffee-drinking women (100-300 mg caffeine/d), RMR increased above baseline over 90 minutes, on average, by 15% in 10 younger (21-31 y) subjects and by 8% in 10 older (50-67 y) subjects after ingesting an approximate 240 mg caffeine dose (Arcerio, 2000).

    • Grade: III
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    In obese Japanese women, what is the acute effect of administration or changes in chemical use of caffeine on resting metabolic rate?
    • Conclusion

      In 10 lean women ((BMI 19.8±0.9 kg/m2(SD); 40-45 y) residing in Japan with daily mild to moderate coffee- or tea-drinking (50-200 mg caffeine/d), individual 30-minute post-caffeine ingestion (200 mg) RMR increases ranged from 10-23% above baseline (Yoshida, 1994). In age-matched, obese (BMI 30.9±1.5 kg/m2 (SD) women, a 30-minute post-caffeine ingestion RMR increase above baseline ranged from 1-25%. Correspondingly, group mean RMR increases were 15% and 14% in lean and obese Japanese women, respectively. In U.S.-residing moderate coffee-drinking women (100-300 mg caffeine/d), RMR increased above baseline over 90 minutes, on average, by 15% in 10 younger (21-31 y) subjects and by 8% in 10 older (50-67 y) subjects after ingesting an approximate 240 mg caffeine dose (Arcerio, 2000). 

    • Grade: III
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    In smokers, what is the acute effect of administration or changes in chemical use of caffeine on resting metabolic rate?
    • Conclusion

      An additive effect on group mean RMR was reported in 18 nonobese men (18-65 y) when caffeine consumption (100 or 200 mg) occurs in addition to nicotine exposure (one or two mg nicotine) (Collins, 1994 and Jessen, 2003). The additive mean RMR change ranged from 6 to 10% above baseline over 30 to 180 minutes (i.e., ½ to 3 hrs) following one to two mg nicotine absorbed via cigarettes or nicotine chewing gum.

    • Grade: III
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    What is the chronic effect of administration or changes in chemical use of caffeine on resting metabolic rate?
    • Conclusion

      In 20 women (23-26 y) with 10 lean (mean BMI 24±1) and 10 age-matched obese individuals (mean BMI 28 ±0.9), the RMR returned to baseline levels after an overnight abstention from drinking 5 cups coffee/d (dosed based on body weight and approximately 1300 mg caffeine/d the day prior.  (Bracco, et al, 1995).

    • Grade: III
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    In older adults, what is the acute effect of administration or changes in chemical use of caffeine on resting metabolic rate?
    • Conclusion

      In 10 older (50-67 y), moderate coffee-drinking women (100-300 mg caffeine/d) women, a blunted thermic effect of caffeine response when expressed as an absolute change over 90 minutes after ingesting approximately 240 mg caffeine, on average (caffeine dosed based on fat-free mass) compared to 10 younger (21-31 y) subjects. There was a statistically-significant body fat percent difference between younger and older women (23.5±5.1 vs. 31.9±5.8 %; P<0.05) (Arcerio, 2000).

    • Grade: III
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    In adult males and adult females, what is the dose-response effect of caffeine?
    • Conclusion

      Available evidence does not permit conclusions on a dose-response effect of caffeine.

    • Grade: V
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.