Impact on energy, sodium and dietary fibre intakes of vegetables prepared at home and away from home in the U.S.A.

OBJECTIVE: To examine how increasing vegetable consumption from foods prepared at home (FAH) and foods prepared away from home (FAFH) would impact energy, dietary fibre and Na (sodium) intakes in the U.S.A.
DESIGN: Using data from the 2003–2004 U.S. National Health and Nutrition Examination Survey, dietary intake data from two separate days were fitted with a first-difference (fixed-effects) model. Vegetables consumed from all sources, including mixed foods and juices, were disaggregated and expressed as amounts equivalent to one cup of whole vegetables.
SETTING: Nationally representative sample of the U.S. population.
SUBJECTS: Individuals aged 2 years and above reporting 2 d of dietary intake data in 2003–2004 (n 7647).
RESULTS: Holding constant the total amount of food consumed, consuming an additional cup of tomatoes and potatoes from FAFH increases energy intake by respectively 1522 and 665 kJ, as compared with 246 and 367 kJ for FAH. Each additional cup of tomatoes from FAH is associated with an additional 179 mg of Na, compared with 113 mg for FAFH. All vegetable consumption increases fibre intake, except for potatoes and tomatoes from FAFH. Dark green and orange vegetables from FAH add the largest amount of fibre (1.38 g/cup).
CONCLUSIONS: Because U.S. consumers frequently consume vegetables as part of mixed foods that add energy and Na, heavier consumption of vegetables as currently prepared raises the energy content and Na density of the overall diet. This is particularly true for vegetables prepared away from home.