Processed Foods Linked to Obesity: Study

The results from a new scientific study support the link between highly processed foods and the growing rates of obesity across the globe.  Highly processed foods (also know as ultra-processed foods) are characterized by being deficient in nutrients (like protein) and natural, whole foods as ingredients that contain exceptionally high levels of synthetic and industrialized food chemicals–many of these additives themselves have been found in previous scientific studies to be linked with serious health outcomes, including weight gain and obesity.


Study overview

The new study was based on a national nutrition and physical activity survey undertaken by the Australian Bureau of Statistics (ABS). The researchers were interested in investigating the hypothesis that diets high in ultra-processed foods were low in protein and therefore triggered overeating. The scientists analyzed data from a cross-sectional survey of nutrition and physical activity in 9,341 adults, known as the National Nutrition and Physical Activity Survey which was conducted from May 2011 to June 2012, with a mean age of 46.3 years. They found the population’s mean energy intake was 8,671 kilojoules (kJ), with the mean percentage of energy from protein being just 18.4 percent, compared with 43.5 percent from carbohydrates and from 30.9 percent from fat, and just 2.2 percent from fiber and 4.3 percent from alcohol.


Results overview

Study participants who consumed lower amounts of protein in their first meal of the day went on to increase their overall food intake in subsequent meals, whereas those who received the recommended amount of protein did not – and, in fact, declined their food intake throughout the day.  Additionally, study participants with a lower proportion of protein than recommended at their first meal consumed more discretionary foods or highly processed foods (energy-dense foods high in saturated fats, sugars, salt, or alcohol) throughout the day, and less of the recommended five food groups (grains; vegetables/legumes; fruit; dairy and meats). (source)  The scientists argue that the body’s powerful demand for protein, and the lack of protein in highly processed foods, is a key driver of energy over-consumption and obesity.

Journal Reference: Grech, A., et al. Macronutrient (im)balance drives energy intake in anobesogenic food environment: An ecological analysis, Obesity Journal (Silver Spring). 2022;30:2156–2166, DOI: 10.1002/oby.2357, Study pdf