Processed foods aka junk foods have become a regular part of many people’s diets because they are convenient, affordable and easy to prepare.
From packaged snacks and sugary drinks to instant meals and processed meats, these foods can save time, but excessive consumption may harm your health.
The World Health Organisation (WHO) recommends that healthy diets should be based largely on a variety of minimally processed and unprocessed foods, while foods high in unhealthy fats, free sugars and sodium should be limited.
Health
Processing itself does not automatically make a food unhealthy. Pasteurised milk, frozen vegetables, tinned beans and other processed foods can still be nutritious. The greater concern is the excessive consumption of highly processed or ultra-processed products with poor nutritional profiles.
Here are 10 ways eating too much of these foods can affect the body:
1. It can contribute to weight gain
Many ultra-processed foods contain substantial amounts of calories, added sugars and unhealthy fats while being relatively low in fibre and other nutrients.
Eating these foods frequently can make it easier to consume more calories than the body needs. Research has consistently found an association between higher consumption of ultra-processed foods and obesity and other measures of excess body fat.
2. It may increase the risk of type 2 diabetes
Frequent consumption of foods high in added sugars and refined carbohydrates can make it more difficult to maintain healthy blood-glucose levels.
A large umbrella review published in the BMJ found evidence linking greater exposure to ultra-processed foods with an increased risk of type 2 diabetes.
Reducing sugary drinks, sweets, and other highly processed foods while eating more whole grains, vegetables, fruits, and legumes can support a healthier dietary pattern.
3. It can raise blood pressure
Some processed foods contain large amounts of sodium, particularly packaged meals, processed meats, salty snacks and other convenience foods.
According to WHO, excessive sodium intake is associated with increased blood pressure, which can contribute to cardiovascular disease. WHO recommends that adults consume less than 5 grams of salt per day, equivalent to less than 2 grams of sodium.
4. It may harm heart health
A diet dominated by ultra-processed foods can expose people to excessive amounts of sodium, saturated fat, added sugars and calories.
The American Heart Association reports that higher consumption of ultra-processed foods is associated with increased cardiovascular risk. Its 2025 scientific advisory also found that dietary patterns high in these foods are associated with adverse cardiometabolic outcomes.
5. It can reduce the amount of fibre in the diet
When highly processed foods replace fruits, vegetables, beans, whole grains, nuts and seeds, people may consume less dietary fibre.
WHO identifies fruits, vegetables, pulses and whole grains as important components of a healthy diet. Fibre also plays an important role in normal digestive function and overall dietary quality.
6. It may affect digestive health
A diet heavily dominated by ultra-processed foods can be low in fibre and diverse plant foods, which may negatively affect dietary quality and the gut environment.
Research has found associations between high ultra-processed food consumption and several gastrointestinal outcomes, although the strength of evidence varies by condition.
his is another reason to include a variety of vegetables, fruits, legumes and whole grains in meals.
7. It can increase exposure to excess sugar
Sugary drinks, confectionery, sweetened cereals, biscuits and many packaged desserts can contain substantial amounts of free or added sugars.
Regularly consuming too much sugar can contribute to excess calorie intake and increase the risk of unhealthy weight gain. WHO therefore recommends limiting free sugars as part of a healthy diet.
8. It may increase the risk of certain chronic diseases
Observational research has linked eating large amounts of ultra-processed foods to several chronic health conditions.
An umbrella review covering nearly 9.9 million participants found associations between greater exposure to ultra-processed foods and multiple adverse health outcomes, including cardiovascular disease, type 2 diabetes and obesity. However, the researchers also noted that the certainty of evidence differed across individual outcomes.
This means such research should be interpreted as evidence of an association rather than proof that every processed food directly causes a particular disease.
9. It can make a healthy diet less balanced
One major problem with excessive processed-food consumption is what it replaces.
For example, someone who frequently fills up on packaged snacks, sugary drinks and fast foods may have less room in their diet for vegetables, fruits, beans, whole grains, nuts and other nutrient-rich foods.
WHO says healthy diets should be diverse and based on adequate, balanced and minimally processed foods.
10. It may increase the risk of poorer overall health over time
The effects of a poor diet may accumulate gradually rather than appearing immediately.
A large body of observational research has associated higher ultra-processed food consumption with several adverse outcomes, including cardiovascular disease, obesity, type 2 diabetes and mortality. A 2025 American Heart Association scientific advisory similarly concluded that high consumption is associated with adverse health outcomes, while noting that more research is needed to understand the precise mechanisms.