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The Link Between Obesity and Diabetes in the UK: A Deep Dive

Written by: Content Team



Time to read 9 min

For people who are obese or excessively overweight, losing weight can be difficult. Unfortunately, obesity increases your chances of developing diabetes, especially if you have a family history of the disease.

The good news is that with the right knowledge and guidance, you can prevent or put off diabetes by losing weight and adopting a healthier lifestyle.

In this article, we’ll explain the link between obesity and diabetes and how you can use this knowledge to improve your health outcomes.

What Causes Type 2 Diabetes?

To this day, scientists haven’t discovered the exact cause of diabetes. However, most studies have pointed to specific risk factors that increase your likelihood of developing type 2 diabetes. Obesity is at the top of the list, with about 80-85% of type 2 diabetics being overweight or obese.

The accumulation of fat around the abdominal organs, called visceral fat, has been linked to higher levels of inflammation. This causes the body to be less sensitive to insulin, known as insulin resistance —the first step to type 2 diabetes.

Obese and overweight people are also more likely to develop cardiovascular disease, high blood pressure, and elevated cholesterol. This cluster of conditions is often referred to as metabolic syndrome, which increases your chances of becoming diabetic because of its negative impact on your blood sugar level.

What Counts as Overweight or Obese?

A woman weighting herself on a weight scale
A woman weighting herself on a weight scale. Source: DepositPhotos

Carrying a bit of excess weight doesn't make you obese or overweight. There are certain criteria for body weight and several methods of measurement that determine just how much excess weight you have.

Once you’ve figured that out, you can deduce how likely or susceptible you are to developing diabetes.

The easiest and most straightforward method is to use the body mass index (BMI), which divides your body weight (in kilograms) by the square of your height (in meters). Depending on the value you get, you’ll fall into one of four categories:

  • Underweight: Less than 18.5
  • Normal weight: 18.5 to 24.9
  • Overweight: 25 to 29.9
  • Obese: 30 to 39.9

Some studies show that individuals with a BMI of 30 or above are up to 80 times more likely to become diabetic than individuals with a BMI below 22.

This is why healthy weight loss, which lowers your body mass index, can help prevent type 2 diabetes.

How Does Obesity Contribute to Diabetes?

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Diabetes Type 2 and pills and supplements laid out on a table. Source: DepositPhotos

There are several theories as to why obesity is such a huge contributor to type 2 diabetes.

Inflammatory Response

Some theories suggest that obesity or excess weight causes an inflammatory response throughout the body, which triggers a series of chemical reactions. These reactions result in high blood sugar or diabetes.

Obese or overweight people tend to have more than average fat cells, especially around the abdominal area. These abdominal fat cells release more pro-inflammatory chemicals than other fat cells, making your muscle and tissue cells more insulin-resistant.

Inflamed cells are much less sensitive to insulin, which means insulin has a harder time pushing excess glucose from the bloodstream into these cells. This is known as insulin resistance, leading to a steady blood glucose buildup. With time, the elevated blood sugar levels result in type 2 diabetes.

This can happen relatively quickly, depending on your body's distribution of fat cells. For example, excess fat cells around the abdominal area or waistline can cause diabetes much more quickly than in other areas.

This is why abdominal or central obesity (obesity with a large waistline) is an extremely high-risk factor for type 2 diabetes.

Abnormal Fat Metabolism

Being obese or having excess body fat affects your body’s ability to metabolize fat. Excess body weight triggers a series of chemical reactions that cause more fat molecules than usual to be deposited into the bloodstream.

These fat cells lead to more pro-inflammatory chemicals, which, in turn, cause more insulin resistance.

Obesity and Diabetes Risk Factors

Obesity and diabetes have many risk factors in common. Here are the most significant ones to look out for:

Inactive (Sedentary) Lifestyle

Your level of physical activity is one of the most important contributors to your risk of obesity, blood glucose levels, and overall health.

Having a sedentary or inactive lifestyle increases your chances of gaining enough weight and developing type 2 diabetes.

People who don’t exercise regularly often have a smaller lean muscle mass and more body fat than those who exercise frequently.

Since muscle cells burn more glucose for energy than fat cells, lower muscle mass means your body burns less glucose. This results in high blood sugar levels stored as more adipose (fat) tissue.

Genetics and Family History

Both diabetes and obesity have a strong genetic factor. That means if you have a family history of diabetes or obesity, especially if it’s a parent or a sibling, you have a greater chance of becoming obese or diabetic.

However, remember that a family history only predisposes you to the condition; it doesn’t cause it. Unhealthy eating habits, lack of exercise, and uncontrolled weight gain are more likely to cause diabetes with or without a genetic factor.

Poor Diet

Poor diet foods: fries, pizza, hot dogs, burgers, soda, chips, keychup, etc
Poor diet foods: fries, pizza, hot dogs, burgers, soda, chips, keychup, etc. Source: DepositPhotos

Eating meals full of sugar or other refined carbohydrates makes it difficult to process the excess glucose that results from digesting this food. Your body has to convert some of this glucose into fat to control your blood sugar levels.

If you’re in caloric surplus often, eating more food than your body requires, the storage of the excess as fat can lead to obesity.

Gestational Diabetes and Obesity

Obesity during pregnancy increases your chances of developing gestational diabetes, which is a temporary form of diabetes that either goes away after childbirth, or develops into type 2 diabetes.

During pregnancy, hormonal and metabolic changes can make it difficult for your body to process glucose. This often causes a temporary increase in your blood sugar level, which should usually revert to normal shortly after delivery.

That said, mothers who have developed gestational diabetes at some point in their lives are more likely to suffer from type 2 diabetes in the future. The risk increases even more for overweight or obese individuals.

Testing for Type 2 Diabetes

Obese and overweight individuals should check their blood sugar levels regularly to make sure they haven’t developed diabetes. Here are a few tests you can take and how to interpret them:

Random Blood Sugar Test

Checking a glucose monitor for blood sugar levels.
Checking a glucose monitor for blood sugar levels.. Source: DepositPhotos

You can do a random blood sugar test using a lancet and a glucometer at home.

This test involves taking a random blood sugar measurement at any time of the day without preparation. 

You don’t need to fast overnight or wait two hours after eating because even if you’ve just eaten, your blood sugar shouldn’t spike above 200 mg/dL unless you have diabetes.

If your blood glucose peaks above 200 mg/dL and you have signs or symptoms of diabetes, you should talk to your healthcare provider right away.

Oral Sugar Tolerance Test

For an oral glucose (sugar) tolerance test, you’re given eight ounces of a carb-rich drink that contains about 75 grams of glucose. The lab tech or nurse will measure your blood sugar before the drink and then one and two hours after. If you get a reading of 200 mg/dL or more after two hours, there’s a high chance you might have diabetes.

The test is done at a lab or a doctor’s office, and you’ll need to fast for eight hours beforehand.

This gauges how well your body lowers your blood glucose levels. It also gives an indication of how well your insulin is working.

Fasting Blood Sugar Test

Another test you can try at home is the fasting blood sugar test. This test measures your basal blood sugar levels without the effect of food or drink.

You’ll need to fast for eight hours, preferably overnight, and then measure your blood sugar first thing in the morning. If you get a fasting blood sugar level of 126 mg/dL or more, there’s a chance you might be diabetic.

HbA1c Test

Blood in a vile for an HbA2c test
Blood in a vile for an HbA2c test. Source: DepositPhotos

An HbA1c test measures your average blood sugar levels over the past two to three months. It’s a much more accurate indicator of glycemic control than other tests.

HbA1c testing is either done in a lab or at a doctor’s office. If you get a reading of 6.5% or above, there’s a chance you might have diabetes.

A reading of 5.7% to 6.4% usually indicates prediabetes, which is a condition where your blood sugar levels are higher than normal but not high enough to warrant a diabetes diagnosis.

However, if you’re obese or overweight, and prediabetic, you should immediately work on controlling your blood sugar levels to avoid developing diabetes.

Preventing Diabetes in Obese Individuals

A woman checking on her midsection for those beautiful love handles
A woman checking on her midsection for those beautiful love handles. Source: DepositPhotos


Getting an adequate amount of weekly physical activity is crucial if you’re worried about developing diabetes. Not only does exercise help you lose weight, which lowers your chances of becoming diabetic, but it also improves your insulin sensitivity.

Studies have shown that following a regular exercise plan can:

  • Prevent metabolic syndrome
  • Improve your cardiovascular fitness
  • Decrease your insulin resistance and, therefore, prevent diabetes
  • Improve your glycemic control

Ideally, you should get about 30-45 minutes of moderate exercise five times weekly. You can split them into as many sessions and days as you want according to your fitness level.

Remember to work out at your own pace initially and not push yourself too hard because consistency is key, and you don’t want to burn out too soon.

Proper Nutrition

A healthy meal plan can help you lose weight and reduce your risk of type 2 diabetes mellitus. It also improves your insulin sensitivity, giving you more control over your blood sugar level.

You can work with your healthcare provider or a nutritionist to create a solid nutrition plan that promotes healthy weight loss. Here are a few tips to get you started:

  • Reduce your portion sizes
  • Avoid carb-rich drinks and meals
  • Avoid refined sugars and processed foods, which reduce your insulin sensitivity
  • Increase your fiber intake
  • Track your calorie intake and try to create a caloric deficit so you can lose weight over time
  • Drink plenty of water

Healthy Weight Loss

Healthy weight loss can help prevent type 2 diabetes. According to the British Nutrition Foundation, losing just 5% of your body weight can significantly reduce your risk of diabetes, heart disease, high blood pressure, and stroke.

For example, if you weigh 140 kg, your initial goal should be to lose about 7 kg. This is easily achievable with proper exercise and nutrition. On average, most people can lose about 0.5 kg to 1 kg per week, which means you can lose about 5% of your body weight in under two months.

With time, you’ll notice your waist circumference, body weight, and insulin requirements dropping as you lose weight and become healthier.

Facts About Obesity

  • The WHO (World Health Organization) estimates that every year, about 2.8 million people die because of obesity or being overweight.
  • Compared to the rest of Europe, the UK has the most cases of adult obesity.
  • A 2021 Health Survey for England showed that about 25.9% of adults were obese, while about 37.9% were overweight.
  • The number of obese people in England nearly doubled from 6.9 million to 13 million in just 20 years (1997 to 2017).


Obesity and diabetes might be two sides of the same coin, but luckily, that means treating one of them can prevent the other.

Since changing habits can promote a healthier lifestyle, working toward the common goal of weight loss and glycemic control is advisable. A diet and exercise plan, with the help of a registered dietician, a personal trainer, or a general practitioner, can put you on the road to becoming healthier, happier, and more fulfilled.

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