Fast food effects: Short-term, long-term, physical, mental, and more Medical News Today Health ConditionsDiscoverToolsConnect Subscribe Is fast food bad for you All you need to know about its nutrition and impacts Medically reviewed by Jerlyn Jones, MS MPA RDN LD CLT, Nutrition — By Timothy Huzar on December 17, 2021 Short-term impacts Long-term impacts Mental health Summary Many fast food establishments now list the number of calories each item contains. However, this is only part of the consideration of whether it is healthy or not.Fast food is typically poor in terms of nutrition. According to a 2015 review, fast food tends to contain various substances that are generally unhealthy. It is high in sugar, salt, saturated or trans fats, and many processed preservatives and ingredients. It also lacks some beneficial nutrients. However, not all fast food has negative impacts, and a person can make an informed choice by researching the nutritional content of particular fast food items. People can find this information on the websites of most major restaurants.That said, even the more healthy fast food items are generally high in sugar, salt, saturated fats, and trans fats. The Office of Disease Prevention and Health Promotion notes that the typical person in the United States consumes too much of these food components. Short-term impacts Share on PinterestSmith Collection/Gado/Getty Images Fast food is typically high in sugar, salt, and saturated or trans fats. The body’s reaction to these nutrients results in a range of short-term impacts when a person eats fast food. Spike in blood sugarFast food breaks down quickly, causing a rapid spike in blood sugar because of the refined carbohydrates and added sugar. In turn, this causes an abnormally large insulin surge, resulting in a drop in blood sugar. This can cause people to feel tired. Insulin promotes further hunger within a short time after the meal. Blood pressureA small 2016 study found that consuming high levels of salt could immediately impact the proper functioning of a person’s blood vessels. Excess sodium intake also has links to fluid retention. Increased inflammationA single serving of fast food could increase inflammation throughout the body. A 2015 study found that one fast food meal high in saturated fat increased airway inflammation in individuals with asthma. This inflammation acts as a trigger for asthma attacks. Affects nutrient intakeFast food does not typically contain fresh fruit and vegetables. If an individual eats fast food frequently, they may find it challenging to reach their recommended daily intake of at least 5 servings of fruit and vegetables. They may also have difficulties reaching their ideal fiber intake, which according to the Food and Drug Administration is 28 grams per day. Binge eating Fast food is highly palatable, meaning the body breaks it down quickly in the mouth, and it does not need much chewing. Therefore, it activates the reward centers in the brain rapidly. This combination trains the palate to prefer these highly processed, highly stimulating foods and reduces someone’s desire for whole, fresh foods. Research from 2018 and other previous studies have suggested a link between fast food consumption and the incidence of food addiction for these low-nutrient items.A small 2017 study of 15 adults found that a single day of high-fat overeating damaged insulin sensitivity. This can then trigger a cycle of binge eating or binge eating disorders. Long-term impacts There is plenty of well-researched evidence showing that regularly eating fast food can harm a person’s health.A 2015 study identified the sometimes irreparable effects of eating fast food. Such risks include obesity, insulin resistance, type 2 diabetes, and various cardiovascular conditions.This is because most fast food is high in sugar, salt, saturated fat, trans fats, processed ingredients, and calories. It is also generally low in antioxidants, fiber, and many other nutrients. Digestive systemMany fast food meals are extremely low in fiber. Doctors associate low-fiber diets with a higher risk of digestive conditions such as constipation and diverticular disease, as well as reductions in healthy gut bacteria. Immunity and inflammationA 2019 review examined the effects of a Western diet on a person’s immune system. This diet consists of high amounts of sugar, salt, and saturated fat from only a few sources.The authors noted that a Western diet could lead to higher inflammation, lower control of infection, higher cancer rates, and a higher risk of allergic and autoinflammatory disease. Memory and learningA 2020 paper suggests a link between unbalanced diets high in saturated fat and simple carbohydrates, typical of fast food, and a lower capacity for memory and learning. This sort of diet may also raise the risk of Alzheimer’s disease and Parkinson’s disease. AllergiesIn a 2018 review, the authors established a link between fast food consumption and an increase in asthma, rhinoconjunctivitis, and eczema. Heart diseaseThe FDA suggests that a diet high in salt often increases a person’s blood pressure, making a person more prone to heart attacks, stroke, kidney disease, or heart disease.The FDA also notes that a diet high in trans fats raises the amount of low-density lipoprotein or “bad” cholesterol and lowers the amount of high-density lipoprotein or “good” cholesterol. This means that a person is more likely to develop heart disease. ObesityThe United States Department of Agriculture points out that typical fast food contains a very high number of calories. If a person eats more calories than they burn each day, they gain weight, which may lead to obesity.According to the Centers for Disease Control and Prevention (CDC), obesity increases a person’s risk of developing a range of serious health conditions. Education Another consequence of younger people regularly eating fast food is their unintentional lack of understanding of basic meal preparation, cooking, and healthy eating. Over time, this perpetuates dependence on fast food, and people may not learn how to prepare healthy, balanced food in the home. Consuming healthy meals can support a person’s long-term health throughout their lifespan. Mental health impactEating lots of fast food could also impact an individual’s mental health and make them more prone to depression and anxiety.A 2021 study compared data from 322 males and 322 females age 30 or older. They found an association between healthy food such as leafy greens, nuts, and fish and positive mood, while the opposite was true of fast food. In addition, women reported significantly more negative associations with fast food than men. Summary Fast food tends to be high in salt, sugar, saturated fats, trans fats, calories, and processed preservatives and ingredients. A wealth of well-conducted research has proven the negative health effects of consuming too much of these food components. In the short term, fast food impacts blood sugar and blood pressure, increases inflammation, and may mean an individual does not eat enough necessary nutrients. In the long term, a diet rich in fast food could lead to issues with digestion, immunity, inflammation, heart health, obesity, and more. Not all fast food is bad, however. Certain menu items might be lower in these substances than others, while some fast food outlets might focus on providing more healthy options. To preserve health, a person should try to identify fast food items that contain less salt, fat, sugar, and total carbohydrates, and generally try to limit the amount of fast food they consume. Last medically reviewed on December 17, 2021 Diabetes Cardiovascular / Cardiology Nutrition / Diet Obesity / Weight Loss / Fitness 20 sourcescollapsed Medical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.Anderson, A. S., et al. (2015). Early skeletal muscle adaptations to short-term high-fat diet in humans before changes in insulin sensitivity. https://pubmed.ncbi.nlm.nih.gov/25820254/Bahadoran, Z., et al. (2015). Fast food pattern and cardiometabolic disorders: A review of current studies. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4772793/Begdache, L., et al. (2019). Assessment of dietary factors, dietary practices and exercise on mental distress in young adults versus matured adults: A cross-sectional study. https://pubmed.ncbi.nlm.nih.gov/29224485/Begdache, L., et al. (2021). Customization of diet may promote exercise and improve mental wellbeing in mature adults: The role of exercise as a mediator. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8161359/Cavka, A., et al. (2016). Short-term high salt intake reduces brachial artery and microvascular function in the absence of changes in blood pressure. https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC6711169/Christ, A., et al. (2019). Western diet and the immune system: An inflammatory connection. https://www.sciencedirect.com/science/article/pii/S1074761319304169Dietary guidelines for Americans 2015-2020. (2015). https://health.gov/sites/default/files/2019-09/2015-2020_Dietary_Guidelines.pdfFast food-Is it the enemy? (2012). https://www.obesityaction.org/resources/fast-food-is-it-the-enemy/Fuhrman J. (2018). The hidden dangers of fast and processed food. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6146358/How to understand and use the nutrition facts label. (2020). https://www.fda.gov/food/new-nutrition-facts-label/how-understand-and-use-nutrition-facts-labelLemeshow, A. R., et al. (2017). Food and beverage consumption and food addiction among women in the Nurses' Health Studies. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5952620/López-Taboada, I., et al. (2020). Western diet: Implications for brain function and behavior. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7719696/Parry, S. A., et al. (2017). A single day of excessive dietary fat intake reduces whole-body insulin sensitivity: The metabolic consequence of binge eating. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579612/Quagliani, D., et al. (2016). Closing America's fiber intake gap: Communication strategies from a food and fiber summit. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124841/Restrepo, B. J., et al. (2018). New national menu labeling provides information consumers can use to help manage their calorie intake. https://www.ers.usda.gov/amber-waves/2018/october/new-national-menu-labeling-provides-information-consumers-can-use-to-help-manage-their-calorie-intake/Sodium in your diet. (2021). https://www.fda.gov/food/nutrition-education-resources-materials/sodium-your-dietSwanson, S. M., et al. (2018). In the clinic: Acute colonic diverticulitis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6430566/The health effects of overweight and obesity. (2020). https://www.cdc.gov/healthyweight/effects/index.htmlTrans fat. (2018). https://www.fda.gov/food/food-additives-petitions/trans-fatWang, C. S., et al. (2018). Is the consumption of fast foods associated with asthma or other allergic diseases? https://pubmed.ncbi.nlm.nih.gov/29974559/ FEEDBACK: Medically reviewed by Jerlyn Jones, MS MPA RDN LD CLT, Nutrition — By Timothy Huzar on December 17, 2021 Latest news Omega-3 may provide a brain boost for people in midlife Seasonal affective disorder (SAD): How to beat it this fall and winter CDC: Monkeypox in the US 'unlikely to be eliminated in the near future' Why are more women prone to Alzheimer's? New clues arise Scientists find previously unknown link between metabolism, brain health Related Coverage Recommended sugar intake: How much should you have per day? Medically reviewed by Natalie Olsen, R.D., L.D., ACSM EP-C The amount of sugar a person should consume varies, depending on their sex and age. 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