Changes in caffeine intake and long-term weight change in men and women.
BACKGROUND
The long-term effects of caffeine intake on weight have not been examined prospectively.


OBJECTIVE
The objective was to assess the relation between caffeine intake and 12-y weight change.


METHODS
We conducted a prospective study of 18 417 men and 39 740 women, with no chronic diseases at baseline, who were followed from 1986 to 1998. Caffeine intake was assessed repeatedly every 2-4 y. Weight change was calculated as the difference between the self-reported weight in 1986 and in 1998.


RESULTS
The participants reported a change in caffeine intake that varied across quintiles, from decreases of 296 and 342 mg/d to increases of 213 and 143 mg/d in men and women, respectively. Age-adjusted models showed a lower mean weight gain in participants who increased their caffeine consumption than in those who decreased their consumption, but the differences between extreme quintiles were small: -0.43 kg (95% CI: -0.17, -0.69) in men and -0.41 kg (95% CI: -0.20, -0.62) in women. After adjustment for potential confounders and baseline and change in total energy intake and other nutrients and foods, the differences remained similar for men and diminished slightly for women (men: -0.43 kg; 95% CI: -0.17, -0.68; women: -0.35; 95% CI: -0.14, -0.56). An increase in coffee and tea consumption was also associated with less weight gain. In men, the association between caffeine intake and weight was stronger in younger participants (P for interaction < 0.001); in women, the association was stronger in those who had a body mass index (in kg/m2) > or = 25, who were less physically active, or who were current smokers (P for interaction < 0.001).


CONCLUSIONS
Increases in caffeine intake may lead to a small reduction in long-term weight gain.
Lopez-Garcia
Esther
E
Department of Nutrition, Harvard School of Public Health, Cambridge, MA, USA.
van Dam
Rob M
RM
Rajpathak
Swapnil
S
Willett
Walter C
WC
Manson
Joann E
JE
Hu
Frank B
FB
D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D002110:Caffeine / Q000008:administration & dosage*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003069:Coffee / Q000737:chemistry*; D016001:Confidence Intervals; D004326:Drinking; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000517:prevention & control*; D016017:Odds Ratio; D011446:Prospective Studies; D012737:Sex Factors; D012907:Smoking; D013662:Tea / Q000737:chemistry*; D015430:Weight Gain / Q000187:drug effects* / Q000502:physiology
D000697:Central Nervous System Stimulants; D003069:Coffee; D013662:Tea; D002110:Caffeine