A recent study across the US revealed that highly processed foods were at the top of the American consumers shopping list, which consisted of more sugar, salt and fat than foods that were less processed—equalling 60% in calories of the total food bought.
Jennifer M. Poti, leader of the research team conducting this study and research assistant professor at the University of North Carolina at Chapel Hill, stated: "Many Americans have strongly held opinions and beliefs about processed foods. Some consider processed foods to be tasty, convenient and affordable choices while others contend that the combination of sugar, fat, salt and flavouring in these foods promotes overeating and contributes to obesity."
The study encompasses 12 years of research, from 2000 to 2012, after a survey of almost 200,000 homes, where the homeowners were asked to record for at least a year all the foods and beverages bought from grocery stores using UPC barcode scanners.
With an average participation of four years, the households collectively bought 1.2 million products, which were then ranked according to each item's degree of food processing by linking every single item to its product description, ingredient list and nutritional information.
Highly processed food were those that comprised industrially manufactured mixtures, such as chips, soda, white bread, cookies, prepared meals and candies. Unprocessed or minimally processed foods were vegetables, frozen fruits, eggs, milk, meat and dried beans.
The products were also categorised according to convenience; i.e. foods that were ready to eat or needed heating or preparation/cooking. That way, 'ready to eat' foods were chips, candy, etc., while frozen meals came under the 'ready to heat' category.
A significant increase was noted in the proportion of calories purchased in ready-to-heat foods at 15.2% in 2012, as per the study. More than 80% of calorie purchases came from ready-to-eat or ready-to-heat form in 2012, which were higher in fat, sugar and salt than food purchases that required preparation.
Poti said: "It is important that when we discuss processed foods, we acknowledge that many processed foods, such as canned vegetables or whole-grain breakfast cereals, are important contributors to nutrition and food security. However, it is the highly processed foods -- those with an extensive degree of processing -- that might potentially be related to obesity."
The results of the survey will be made public during Experimental Biology 2015 at the annual Meeting of The American Society for Nutrition (ASN).
