Nutritionists and health food campaigners have been saying it for years, but now a new study from the US Department of Agriculture has confirmed it: people who eat fast food have a greater calorie intake than those who do not, and therefore have a greater risk of overweight or obesity.
A study of 9,000 US citizens by the USDA's Agricultural Research Service (ARS) shows that, every day, around a quarter of US adults over the age of 20 eat fast food and drink twice as many sugary, carbonated soft drinks as those who do not, and that fast food eaters consumed substantially higher amounts of calories, fats, carbohydrates, added sugars and proteins than their non-fast food-eating counterparts.
The study was led by ARS nutritionist Shanthy A. Bowman, based at the agency's Human Nutrition Research Center. The study appears in the currentJournal of the American College of Nutrition.
The nationally representative respondents were surveyed for two non-consecutive days by Bowman's team of researchers. Those who consumed fast food on either or both days, when compared to those who did not, showed higher mean body mass indexes and higher odds of being overweight.
Although fast food provided one-third of some respondents' daily caloric intakes, those meals included almost no milk, fruit or fruit juices, which are important nutrient sources among key food groups. In fact, as the frequency of fast food consumption increased from zero days to two days, the intake levels of vitamins A and C, carotenes, calcium, phosphorus and magnesium decreased, the study found.
The existing USDA dietary intake survey data, which the authors analysed, was collected in the mid-1990s. The results showed a significant increase in fast food consumption from the early 1990s, when the previous survey had been conducted.
Increased work-week hours and a doubling of the number of US fast food restaurants to about 250,000 in the past 25 years have influenced the amount of time people spend on food shopping and meal preparation, the researchers said, adding that planning weekly meals and related grocery shopping could help adults resist the fast meal decisions that lead to grabbing a quick bite.