Junk food in the context of Breakfast cereal

Lifestyle diseases can be defined as the diseases linked to the manner in which a person lives their life. These diseases are non-communicable, and can be caused by lack of physical activity, unhealthy eating, alcohol, substance use disorders and smoking tobacco, which can lead to heart disease, stroke, obesity, type II diabetes and lung cancer. The diseases that appear to increase in frequency as countries become more industrialized and people live longer include Alzheimer's disease, arthritis, atherosclerosis, asthma, cancer, chronic liver disease or cirrhosis, chronic obstructive pulmonary disease, colitis, irritable bowel syndrome, type 2 diabetes, heart disease, hypertension, metabolic syndrome, chronic kidney failure, osteoporosis, PCOD, stroke, depression, obesity and vascular dementia.

Concerns were raised in 2011 that lifestyle diseases could soon have an impact on the workforce and the cost of health care. Treating these non-communicable diseases can be expensive. It can be critical for the patient's health to receive primary prevention and identify early symptoms of these non-communicable diseases. These lifestyle diseases are expected to increase throughout the years if people do not improve their lifestyle choices.

An ultra-processed food (UPF) is a grouping of processed food characterized by relatively involved methods of production. There is no simple definition of UPF, but they are generally understood to be an industrial creation derived from natural food or synthesized from other organic compounds. The resulting products are designed to be highly profitable, convenient, and hyperpalatable, often through food additives such as preservatives, colourings, and flavourings. UPFs have often undergone processes such as moulding/extruding, hydrogenation, or frying.

Ultra-processed foods first became ubiquitous in the 1980s, though the term "ultra-processed food" gained prominence from a 2009 paper by Brazilian researchers as part of the Nova classification system. In the Nova system, UPFs include most bread and other mass-produced baked goods, frozen pizza, instant noodles, flavored yogurt, fruit and milk drinks, diet products, baby food, and most of what is considered junk food. The Nova definition considers ingredients, processing, and how products are marketed; nutritional content is not evaluated. As of 2024, research into the effects of UPFs is rapidly evolving.