Why is visceral fat the most important fat to lose?

Dietitian, Annica Rust, expands on why visceral fat is the most important fat to lose and suggest ways to do so.


Obesity on the rise

Globally and in South Africa, the prevalence of obesity is on the rise as seen in figure 1 below:3

Figure 1: Prevalence of Obesity in South Africa (World Obesity)

Obesity is defined as an abnormal or excessive fat accumulation that puts your health at risk. Typically, a body mass index (BMI) over 25 kg/m2 is considered overweight, and over 30 kg/m2 is obese.1

Obesity is often associated with high visceral fat and is a major risk factor for the development of chronic diseases, such as Type 2 diabetes. However, we often overlook normal weight individuals or perceive them as being healthy. This is not necessarily the case, as being thin or having a normal weight doesn’t actually equate to being healthy or having a normal amount of visceral fat.

Thin on the outside, fat on the inside (TOFI) as seen in figure 2, remains a possibility for individuals with a perceived normal BMI. These individuals are at risk of having high an amount of visceral fat and are often overlooked for being at risk of chronic diseases. This phenomenon is known as metabolically obese, normal weight (MONW). Signs of MONW, include excess visceral fat, reduced muscle mass and low fitness levels.3

Figure 2: Thin on the outside, fat on the inside.

Subcutaneous fat vs visceral fat

Subcutaneous fat is a layer of fat just below the skin, whilst visceral fat or also known as abdominal fat, is the fat surrounding our internal organs. These include the liver, pancreas and intestines, as seen in figure 3 below.2

Figure 3: Subcutaneous versus visceral fat.

Why is visceral fat dangerous?

The danger of visceral fat is related to the release of hormones, such as resistin, leptin, adiponectin, and a protein tumour necrosis-factor-alpha (TNF-alpha). These all contribute to an increase in the total systemic inflammation in the body, which in turn can damage arteries, leading to heart disease.

The inflammation further increases the risk of blood clots that can cause a stroke. Furthermore, a high visceral fat amount has been linked to Type 2 diabetes, sleep apnoea, non-alcoholic fatty liver disease, high blood pressure, and high cholesterol. Having high visceral fat also increases the risk for developing cancer.4

How is visceral fat measured?

A waist size line that is more than 94cm for men and over 80cm for woman are considered to be high and may be associated with high visceral fat. Bone density scans and high-tech scales can also measure visceral fat, but the scales vary in accuracy and cost.

How do I lose visceral fat?

Dietary management, exercise, looking after your mental health and managing stress, and improving sleep patterns remains key practices to lowering your body-and-visceral fat.

1. Dietary management

A good start will be to lower saturated and trans fats intake in your diet. Saturated fat increase LDL cholesterol, also known as the bad cholesterol in the blood. Common sources of saturated fats include animal products like butter, meat fat, beef, lamb, chicken skin and full-cream dairy foods. Trans fats are found in some processed foods, like pastries, biscuits and deep-fried foods. Focus on food items with less than 1.5g of saturated fats per 100g and minimal to none trans fats.

Numerous studies have found that the Mediterranean diet with a focus on monounsaturated fat intake, appears to have a positive effect on decreasing visceral fat. However, adequate protein intake, combined with a reduction in saturated fats, refined sugar and energy also remains important.5

What is the Mediterranean diet?5

The foundation for the Mediterranean diet includes an abundance of fruits, vegetables, wholegrains, nuts and legumes. Olive oil is the principal source of fat in this diet. Dairy products, such as cheese and yogurt, should be consumed daily, in moderation. Fish and poultry can be consumed a few times a week, with limited amounts of red meat.

How to practically implement the Mediterranean diet5

  1. Switch to extra virgin olive oil when cooking.
  2. Choose nuts as a snack instead of processed snacks such as crisps.
  3. Focus on eating more wholegrain products, such as whole-wheat bread, bulgur, barley, couscous and whole-wheat pasta.
  4. Choose a variety of vegetables and add an extra serving of vegetables to both lunch and dinner, aiming for three to four servings a day. And remember your healthy green salad.
  5. Try to incorporate two to three servings of legumes (lentils, chickpeas, beans, and peas) to a meal during the week.
  6. Limit your red meat intake to twice a week and focus on adding more lean poultry and fish.
  7. Limit your alcohol intake, women should only have one drink per day and men only two drinks. One drink of alcohol = 125ml wine, 330ml beer or 45ml of spirits.
  8. Cut out sugary beverages (fizzy drinks and juice) and replace them with water.
  9. Replace high-fat, high-sugar desserts with fresh fruit. Aim for three servings of fresh fruit a day. Save cakes and pastries for special occasions.

2. Exercise

Regular exercise is also important. Exercising four times a week has been proven to be effective in reducing visceral fat. Two sessions should ideally be high-intensity in a week, such as interval training or fast cycling, and two moderate intensity (30 minutes of brisk walking, cross-training or swimming).

3. Sleep

An association has been found between a shorter duration of sleep and obesity and a higher visceral fat count. It’s thus crucial to form healthy sleeping habits and to aim for more than eight hours of good quality sleep per night.6 

4. Stress management

Prolonged stress may increase cortisol release which in turn may increase insulin resistance and visceral fat. Accordingly, it’s important to manage your stress as it has the potential of increasing the risk of developing Type 2 diabetes7.

Losing visceral fat requires a lifestyle change, which includes healthy diet habits, regular exercise, controlling stress and improving sleep patterns. Please contact a registered dietitian for an individualised dietary approach to lose your visceral fat.


References

  1. World Health Organisation (WHO). 2022. Obesity. https://www.who.int/health-topics/obesity#tab=tab_1 [27 November 2022].
  2. Mahan, L.K., Escott-Stump, S., & Raymond, J.L. (eds). Krause’s food and the nutrition care process. 13th ed. St Louis, MO: Elsevier Saunders.
  3. Obesity phenotypes De Lorenzo, A., Soldati, L., Sarlo., F., Calvani., M., De Lorenzo, N & Di Renzo,L.  2016. New obesity classification criteria as a tool for bariatric surgery indication. World Journal of Gastroenterology, 22(2).
  4. 2022. Visceral fat: health problems beneath the surface. https://www.hcf.com.au/health-agenda/food-diet/nutrition/reduce-visceral-fat [27 November 2022].
  5. Harvard Health Publishing.2022. A practical guide to the Mediterranean diet. https://www.health.harvard.edu/blog/a-practical-guide-to-the-mediterranean-diet-2019032116194 [27 November 2022].
  6. Fan, Y., Zhang, L., Wang, Y., Li, C., Zhang, B., He, J., Guo, P. & Qi, X. 2021. Gender differences in the association between sleep duration and body mass index, percentage of body fat and visceral fat area among chinese adults: a cross-sectional study. BMC Endocrine Disorders, 21(247).
  7. Gianotti, Ll., Belcastro, S., D’Agnano. & Tassone, F. 2021. The Stress Axis in Obesity and Diabetes Mellitus: An Update.  Endocrines, 2021, 2(1).

 

MEET THE EXPERT


Annica Rust is a registered dietitian practicing at the Breast Care Unit in Netcare Milpark Hospital as well as in Bryanston. She assists with medical nutritional therapy for cancer prevention, treatment, survivorship and palliation. She gives individualised nutritional care to prevent or reverse nutrient deficiencies, nutrition-related side effects and malnutrition to maximise quality of life.


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