Metabolism refers to the bodily process of extracting energy from food. Diabetes affects metabolism by reducing insulin levels. This in turn prevents the body from storing the energy it gets from food for later use.

In type 1 diabetes, this happens because the immune system is attacking the cells that make insulin, which are in the pancreas. In type 2 diabetes, the body stops responding to insulin as well as it should.

In this article, we will look at diabetes and metabolism more closely.

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Metabolism is the process through which the body creates energy from the food and drink a person consumes.

After eating, the body begins breaking down carbohydrates, proteins, and fats in order to release energy from them. The body then uses this energy to keep organs and biological processes working.

There are three main ways that the body uses up energy:

  • Resting energy expenditure: This refers to the energy the body uses at rest. It is similar to the basal metabolic rate (BMR), which is the energy the body needs for its most basic and essential functions, such as breathing.
  • Diet-induced energy expenditure: This refers to the energy a person uses for digestion. Another term for it is the thermic effect of food.
  • Activity-induced energy expenditure: This refers to the energy someone uses for physical activity. The more active a person is, the higher the energy expenditure.

People who have slow metabolisms typically have a low BMR. This means they require fewer calories at rest than someone with a faster metabolism, or a high BMR.

There are many factors that can raise or lower BMR, including:

  • muscle mass
  • bone size and density
  • body fat
  • age, as muscle mass tends to decrease as people get older
  • genetics

Diabetes is a metabolic disorder, which means it directly impairs the body’s ability to release and store energy from food. This happens due to problems with insulin production.

When a person eats carbohydrates, the body begins to break them down into their simplest form, which is glucose. This glucose then enters the bloodstream, delivering energy to cells around the body.

Usually, if blood glucose levels are too high, the pancreas releases insulin. This hormone tells the liver to remove glucose from the blood and turn it into glycogen, which the body can use later.

However, in people with diabetes, insulin levels become lower than they need to be. This leaves high levels of glucose in the blood, which can lead to serious consequences if left untreated.

There are two main types of diabetes:

Type 1 diabetes

In type 1 diabetes, a person has very low or absent insulin levels. This occurs because the immune system mistakenly attacks the cells in the pancreas that make it. As a result, people with type 1 diabetes need insulin injections throughout their lives.

Individuals usually receive a type 1 diabetes diagnosis in childhood or when they are young adults. It accounts for 5–10% of all cases of diabetes.

Type 2 diabetes

In people with type 2 diabetes, the body stops responding as well to insulin, leading to high blood glucose levels. Over time, the pancreas produces increasing amounts of insulin to try to keep up.

This creates a deficit, where the body does not have the capacity to deal with the amount of glucose in the blood. Eventually, the cells in the pancreas that produce insulin wear out.

Type 2 diabetes is far more common than type 1 and accounts for 90% of all cases of diabetes.

In addition to carbohydrates, the body can use protein as an energy source. In some situations, the body can break down protein from its own muscles for energy. Experts term this catabolism.

An older 2008 article notes that people with type 1 diabetes who do not have enough insulin from their medication may experience catabolism, leading to a significant reduction in muscle mass. This same effect does not occur in people with type 2 diabetes.

When a person has enough insulin, their body is able to use and store glucose effectively.

However, without insulin, the body can switch to using stored fat instead. This happens through a process that experts refer to as ketosis.

During ketosis, the body releases ketones, which are chemicals that break down from fats. If ketone levels become too high, they can make the blood acidic. This results in a serious condition known as diabetic ketoacidosis (DKA).

DKA mainly occurs in people with type 1 diabetes, but it can also develop in those with type 2 diabetes. It is a potentially life threatening condition that requires emergency treatment.

Blood ketone monitors or urine testing strips can help people check their ketone levels.

Learn about the symptoms of DKA here.

Diet, exercise, and body weight have a significant influence on metabolism and the risk of developing type 2 diabetes.

Diet

A diet high in simple carbohydrates that digest quickly and provide more energy than a person needs can elevate blood glucose levels.

If the levels remain high over time, the body may not be able to produce enough insulin to lower them to a healthy level. This in turn can contribute to the development of type 2 diabetes.

Additionally, simple carbohydrates are not as filling as other foods, despite their high energy content. This can mean people feel hungrier and eat more food as a result, further raising blood glucose.

Simple carbohydrates are present in foods that contain a lot of sugar, such as candy, sugary drinks, and ice cream.

Complex carbohydrates take longer to break down, and they release their energy over a longer period of time. These include foods such as whole grains, beans, and high fiber vegetables.

Exercise

When someone engages in exercise or other physical activity, their activity-induced energy expenditure goes up. This means the body can use up glucose that is circulating in the blood, lowering blood glucose levels.

Strengthening exercises can also build muscle. Muscle cells require energy even when not in use, so the more muscle a person has, the more calories they burn at rest.

Body weight

Body weight also has an impact on metabolism.

A high body weight increases the risk of developing type 2 diabetes by making cells in the body less sensitive to insulin. This means cells will not store excess glucose as effectively, making high blood glucose more likely.

A combination of excess weight, a diet high in simple carbohydrates, and low levels of physical activity can contribute to the development of type 2 diabetes.

Insulin medication stimulates the muscle, liver, and fat cells to absorb and store glucose as glycogen. When this happens, a person’s blood glucose levels reduce.

In people with diabetes, the aim is to achieve a balance of insulin and blood glucose. This means that a person has enough energy ready to use but not so much that they risk long-term health complications.

Using too much insulin can reduce blood glucose to dangerous levels, causing hypoglycemia. Not using enough causes hyperglycemia.

Diabetes impairs the body’s metabolism, affecting how it processes and stores energy. This happens due to a lack of insulin, which is a hormone that controls the amount of glucose in the blood.

If there is not enough insulin, blood glucose levels can become too high, which causes a range of problems over time.

Getting exercise, strengthening muscles, and reaching or maintaining a moderate weight can improve blood sugar levels in people with type 2 diabetes by increasing BMR and insulin sensitivity.

Complex carbohydrates can also help with maintaining steady blood glucose levels throughout the day.