The term "fast food" generally refers to food that people intend to consume quickly, either on- or off-site. There is plenty of well-researched evidence demonstrating the various negative health effects of eating and overeating fast food, in both the short- and long-term.
Many fast food establishments now list the number of calories each of their items contains. However, this is only part of the consideration of whether it is healthful or not.
Fast food is typically very poor in terms of nutrition. According to a study paper in the journal
Not all fast food is bad, and a person can make an informed choice by doing research to find out the nutritional content of particular fast food items. These are available on the websites of most major restaurants.
However, even the more healthful fast food items are generally high in sugar, salt, saturated fats and trans fats. The
Because fast food is typically high in sugar, salt, and saturated or trans fats, looking at the short-term effects of these nutrients can help determine what happens in the short-term when a person eats fast food.
The results of a small study in the journal
Doctors, dietitians, and other health experts believe that this is because sugary foods are worse at providing satiety, or a sense of fullness.
Also, high-carbohydrate foods increase the body's demand for insulin, which also promotes more hunger within a shorter amount of time after the meal.
Experts believe that the more hungry a person is before their next meal, the more likely they are to eat more calories than necessary.
A small study in the
Fast food is also often very low in fresh fruit and vegetables, which makes it hard for people to reach their recommended daily intake of at least 5 servings. It may also be hard for them to reach their ideal fiber intake, which is at least 25 grams per day.
Fast food is highly palatable, meaning that it is very quickly broken down in the mouth, does not require much chewing, and activates the reward centers in the brain rapidly.
This combination trains the palate to prefer these highly processed, highly stimulating foods. This reduces someone's desire for whole, fresh foods.
There is plenty of well-researched evidence showing that regularly eating fast food can harm a person's health.
This is because most fast food is high in sugar, salt, saturated fat and trans fats, processed ingredients, and calories, and low in antioxidants, fiber, and many other nutrients.
Many fast food meals are very low in fiber. A low-fiber diet is associated with a higher risk of digestive conditions such as constipation and
A study in the journal
A study in the
A study in the journal Appetite also suggests that there is a causal link between a diet high in saturated fat and simple carbohydrates, typical of much 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.
The Obesity Action Coalition point out that typical fast food contains a very high number of calories. If a person eats more calories than they are burning during each day, they will put on weight, which may lead to obesity.
According to the
Another consequence of younger people regularly eating fast food is their uninentional lack of understanding of basic meal preparation, cooking, and healthful eating.
Over time, this perpetuates a dependence on fast food, and people may not learn how to prepare healthful, balanced food in the home. Consuming such meals can support a person's long-term health throughout their lifespan.
Fast food tends to be high in salt, sugar, saturated fats, trans fats, calories, and processed preservatives and ingredients.
A lot of well-conducted research has proven the negative health effects of consuming too much of these.
Not all fast food is bad, however. Some menu items might be lower in these substances than others, while some fast food outlets might focus on providing more healthful options.
However, this is not the case for the majority of fast food outlets, or the majority of food items they sell.
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 restrict the amount of fast food they consume.