Today, one of the factors that is becoming widespread in dietary habits and seen as a responsible factor for the increasing epidemic of obesity is the excessive consumption of ultra processed foods. Ultra processed foods have been described as ‘‘formulations mostly of cheap industrial sources of dietary energy and nutrients plus additives, using a series of processes and containing minimal whole food”.
Based on the NOVA food classification, foods are divided into four groups: unprocessed, minimally processed, processed and ultra-processed, and ultra processed foods represent the 4. group. To illustrate, fresh vegetables and fruits are categorized as group 1(unprocessed foods). On the other hand snacks such as biscuits, chocolare are categorized as group 4(ultra processed foods). In addition, sugar sweetened beverages(SSBs) like cola, ice tea; fast foods like hamburger, pizza, hot dog; other sugary or salty snacks which are sold in markets are also classified as ultra processed foods.
Ultra-processed foods have poor nutritional quality. In other words, they are low in vitamins and minerals. On the other hand, these foods are high in several dietary factors which people should consume in limit such as energy, refined carbohydrate, added sugar, sodium, saturated fat. For example, the amount of sodium that could be taken daily for adults should be limited to 2300 mg (1 teaspoon of salt) according to WHO. Nevertheless, it is not possible to comply with this limit when eating too much ultra processed foods. Typically, on an average American diet, approximately 70% of sodium taken daily is thought to come from ultra-processed foods. The most important known adverse effect of high sodium intake on health is that it increases the risk of hypertension by increasing blood pressure (2). Another example is the added sugar limit.
It is recommended that no more than 10% of the daily intake of energy comes from added sugar in adults and no more than 5% for children (3). Individuals and children who regularly eat ultra-processed foods such as chocolates and biscuits can easily exceed this limits. Added sugar has different many forms and names including sucrose, brown sugar, agave syrup etc. One of the most popular added sugars is high-fructose corn syrup (HFCS). The limits for added sugar should be applied to every type of sugars. Because high consumption of additive sugar is associated with many health problems such as obesity, type 2 diabetes and heart disease.
One of the definitions used in nutritional science especially to define the food environment is “obesogenic environment ”. The obesogenicity of an environment has been defined as “the sum of influences that the surroundings, opportunities, or conditions of life have on promoting obesity in individuals or populations.” Obesogenic environments (obesity-promoting) are perceived to be a driving force behind the escalating obesity epidemic (4). To give an example from today's lifestyle, one foot of the obesogenic environment constitutes a nutrient environment and the other foot creates a physical activity environment that triggers sedentary lifestyle.
A randomized controlled study of 20 individuals published in Cell Journal in the past months by Kevin et al. The researchers has investigated in this study that whether ultra-processed food-rich diet is a triggering factor for excessive energy intake and obesity. The duration of the study was fourteen days and the participants were divided into two groups: Ultra Processed Food based diet or Unprocessed/ Minimally Processed Food based diet. The meals were supplied during the study time. The important findings of the study are as follows:
-
Ad libitum intake was 500 kcal/day more on the ultraprocessed vs. unprocessed diet.
-
Body weight changes were highly correlated with diet differences in energy intake.
In conclusion, the findings of this study show that reducing ultra-processed food consumption may be an important strategy in prevention of obesity. In addition, further studies are needed to show that ultra-processed foods provide causality rather than a correlation for obesity especially with more randomised controlled trials.
