Being overweight or carrying excess body fat is a risk factor of type 2 diabetes, yet there are many other causes behind the condition. Someone of a healthy weight could actually be diagnosed with type 2 diabetes.

We take a look at some of the contributing factors behind ‘skinny’ type 2 diabetes.

Insulin resistance and fatty liver 

Our body produces the hormone insulin to utilise glucose as fuel or store it for later use in the muscle and liver, or as body fat. The main characteristic of type 2 diabetes, insulin resistance, occurs when the cells in the body can no longer respond effectively to insulin. Insulin resistance leads to higher insulin levels as the body attempts to maintain healthy blood glucose levels, but this creates a vicious cycle that further promotes insulin resistance. Eventually, the body can no longer keep up with the increasing insulin requirements, resulting in excess glucose in the bloodstream, also known as hyperglycaemia.

While one of the leading causes of insulin resistance is being overweight or obese, there are several other factors that are also associated with the condition:

  • You are white and over 40 or are over 25 and are African-Caribbean, Black African, or South Asian.
  • You have a close family member who already has the condition.
  • You have high blood pressure or cholesterol.
  • You have a sedentary lifestyle.
  • Find out about other risk factors.

Insulin resistance and type 2 diabetes are also associated with non-alcoholic fatty liver disease (NAFLD). Insulin resistance results in increased levels of fat in the blood, which can accumulate in the liver. High insulin levels (hyperinsulinemia) also promote the production of liver fat from excess sugar in the body.[1]

Over time, having too much fat in the liver creates more insulin resistance, in turn leading to the production of even more insulin. [2]

Read more about non-alcoholic fatty liver disease.

Thin outside, fat inside (TOFI)

We all have a layer of fat under our skin called subcutaneous fat. Although subcutaneous fat is part of our overall weight, visceral fat stored within our abdominal cavity is associated with health conditions including type 2 diabetes, heart disease and cancer.

Visceral fat can be found wrapped around vital organs such as the liver, pancreas and intestines and is often associated with insulin resistance.

The term TOFI or ‘thin outside, fat inside’ is attributed to individuals who do not look overweight but have a disproportionally high amount of abdominal fat. Someone with TOFI has less subcutaneous fat but large amounts of visceral fat. Those with TOFI have been identified as being at a higher risk of developing insulin resistance.[3]

Someone who is unable to store subcutaneous fat might have a condition called lipodystrophy.[4] Individuals with lipodystrophy have an increased risk of insulin resistance and type 2 diabetes, with almost all of their fat stored as visceral fat within the abdomen.

As discussed above, while being overweight is associated with type 2 diabetes, there are various other factors at play. Someone may be considered a healthy weight but will be diagnosed with the condition. In these individuals, type 2 diabetes might be caused by insulin resistance and the accumulation of visceral fat around internal organs, including the liver.

Adopting a healthy lifestyle can help reduce the risk of developing type 2 diabetes. Following a low-carb diet and regularly exercising can lower insulin levels within normal range and keep insulin resistance at bay.


[1] Marjot, T. et al (2019). Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management. Endrocine Reviews, 41 (1), 66-117.

[2] Intensive Dietary Program (n.d). Fatty Liver – T2D 25.

[3] Zdrojewicz, Z. et al. (2017). TOFI phenotype – its effect on the occurrence of diabetes. Pediatric Endocrinology Diabetes and Metbolism, 23(2), 96-100.

[4] Herranz, P., de Lucas, R., Perez-Espana, L., & Mayor, M. (2008). Lipodystrophy syndromes. Dermatologic clinics, 26 (4), 569-78.

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