title: Trends in energy and macronutrient intakes by weight status over four decades.
abstract: OBJECTIVE
  To examine whether the recent increasing prevalence of obesity was accompanied by variations in energy and macronutrient intakes by weight status.
  
  
  METHODS
  Time series of cross-sectional surveys.
  
  
  METHODS
  National Health and Nutrition Examination Surveys (NHANES) in the USA.
  
  
  METHODS
  Adult participants of NHANES I (1971-1974), II (1976-1980), III (1988-1994) and continuous (1999-2004).
  
  
  RESULTS
  Daily energy intake increased over time for men (9832 to 11 652 kJ, P < 0·01) and women (6418 to 8142 kJ, P < 0·01) in all BMI classes. Percentage of energy intake from carbohydrate increased over time (men: 42·7% to 48·0%, P < 0·01; women: 45·4% to 50·6%, P < 0·01), whereas percentage of energy intake from fat (men: 36·7% to 33·1%, P < 0·01; women: 36·1% to 33·8%, P < 0·01) and protein (men: 16·4% to 15·1%, P < 0·01; women: 16·9% to 14·7%, P < 0·01) decreased. With surveys combined, daily energy intake varied among BMI classes for women (underweight/normal weight: 7460 kJ; overweight: 6799 kJ; obese I: 7033 kJ; obese II/III: 7401 kJ; P < 0·01) but not men. Percentage of energy intake from carbohydrate decreased with increasing BMI class (men: 46·6% to 45·5%, P < 0·01; women: 49·0% to 48·6%, P < 0·01) whereas percentage of energy intake from fat (men: 34·3% to 36·5%, P < 0·01; women: 34·4% to 35·4%, P < 0·01) and protein (men: 15·3% to 16·5%, P < 0·01; women: 15·2% to 16·0%, P < 0·01) increased. Interactions of survey period and BMI class were not statistically significant.
  
  
  CONCLUSIONS
  Time trends in energy and macronutrient intakes were similar across BMI classes. Research examining how individuals respond differently to varying dietary compositions may provide greater insight about contributors to the rise in obesity.
authors: 1 Center for Health Services Research in Primary Care, Department of Veterans Affairs, HSR&D (152), VA Medical Center, 508 Fulton Street, Durham, NC 27705, USA.
authors: William S
authors: WS
authors: Yancy
authors: 3 Research Triangle Institute, Research Triangle Park, NC, USA.
authors: Chi-Chuan
authors: CC
authors: Wang
authors: 1 Center for Health Services Research in Primary Care, Department of Veterans Affairs, HSR&D (152), VA Medical Center, 508 Fulton Street, Durham, NC 27705, USA.
authors: Matthew L
authors: ML
authors: Maciejewski
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D001835:Body Weight; D003430:Cross-Sectional Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D009749:Nutrition Surveys; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology*; D015995:Prevalence; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins