Trends in energy intake among adults in the United States: findings from NHANES.

BACKGROUND Energy intake is a key determinant of weight. OBJECTIVE Our objective was to examine trends in energy intake in adults in the United States from 1971-1975 to 2009-2010. DESIGN The study was a trend analysis of 9 national surveys in the United States that included data from 63,761 adults aged 20-74 y. RESULTS Adjusted mean energy intake increased from 1955 kcal/d during 1971-1975 to 2269 kcal/d during 2003-2004 and then declined to 2195 kcal/d during 2009-2010 (P-linear trend < 0.001, P-nonlinear trend < 0.001). During the period from 1999-2000 to 2009-2010, no significant linear trend in energy intake was observed (P = 0.058), but a significant nonlinear trend was noted (P = 0.042), indicating a downward trend in energy intake. Significant decreases in energy intake from 1999-2000 to 2009-2010 were noted for participants aged 20-39 y, men, women, and participants with a BMI (in kg/m(2)) of 18.5 to <25 and ≥30. CONCLUSION After decades of increases, mean energy intake has decreased significantly since 2003-2004.