First, it is important to stress that you don’t need to stop eating ultra-processed foods entirely. This would actually be a near impossible task and there is room for all foods within a balanced diet. Food processing is essential for food safety and extension of shelf life, which reduces food waste. Moreover, not all ultra-processed foods are high energy and nutrient poor e.g., low sugar canned beans.
The reason to limit the intake of unhealthy ultra-processed foods is that there is a growing body of evidence linking over consumption of these foods to poorer health and increased morbidity and mortality from several chronic diseases. Here are some of the reported associations:
Our own research (PREDICT 1) shows an association between ultra-processed food intake and body compositions. A 10% increase in energy intake from ultra-processed foods was associated with an increase of 0.8 kg/m2 in BMI and 1.9 cm in waist circumference after adjustment for age, sex, ethnicity, total energy intake, and smoking status.
Increase in all-cause mortality. Romeiro Ferreiro et al. 2021 report an increase of 15% in the hazard of all-cause mortality for every 10% increase in the energy intake from ultra-processed foods. This trend is supported by other studies such as Rico-campa et al. 2019, which found that high consumption of ultra-processed foods (>4 servings daily) was significantly associated with a 62% relatively higher hazard of mortality, with each additional serving being associated with an 18% higher hazard of all cause mortality.
Excess calorie intake and weight gain (e.g., Hall et al. 2019, Forde et al 2020, Pagliai et al. 2020). Specifically, Romeiro Ferreiro et al. 2021 found a 6% higher risk of being obese for every 10% increase in ultra-processed food intake.
Faster eating rates (e.g., Hall et al. 2019), which have been associated with higher energy intake (e.g., McCrickerd et al. 2017, Robinson et al. 2014). Forde et al 2018 suggest that a 20% change in eating rate can impact energy intake by between 10–13%.
Increased overall risk of cardiovascular, coronary heart and cerebrovascular disease (e.g., Srour et al 2019).
Higher risk of hypertension (e.g., de Oliveira da Silva Scaranni et al. 2021, Pagliai et al. 2020, Nardocci et al. 2020).
Higher risk of type 2 diabetes (e.g., Srour et al. 2019).
Non-communicable diseases like metabolic syndrome (e.g., Atzeni et al. 2022, Pagliai et al. 2020, Lane et al. 2020).
Poorer mental health, including increased likelihood of depression and anxiety (e.g., Hecht et al. 2022).
Cognitive decline (e.g., Gomes Goncalves et al. 2022, Li et al. 2022).
Certain cancers including breast, prostate, and colorectal cancer (e.g., Fiolet et al. 2018).
It is important to note that while an association may be reported, causality may be difficult to ascertain and it could be that the association was also influenced by other factors. In addition, the effect sizes vary by condition and may be sensitive to a range of factors like your genetics.