How to Lose Visceral Fat: Why Belly Fat Is Different and What Actually Burns It
One of the questions I get most often, on calls and in clinic, is some version of “why can’t I lose belly fat no matter what I do?” I think everyone who does not have a six-pack assumes a six-pack means healthy and fit. I had one once. It was 1988, it lasted about 35 minutes, and I never saw it again. So I am not writing this from the other side of the fence.
Why can’t you lose belly fat no matter what you do?
Because belly fat is not the same fat as the rest of you, and it is driven by insulin resistance. Until the insulin problem is addressed, crunches, cutting calories on their own, and most of what people try will not touch it. Once it is addressed, belly fat is the first fat to go. That is the good news hidden inside the bad.
What is the difference between visceral fat and subcutaneous fat?
Subcutaneous fat is the fat right under your skin. Everyone has it, genetically, as a storehouse for extra energy, and it is not bad for you. Visceral fat is the fat that accumulates around your organs, inside the abdomen, and it is built from energy you took in and did not burn. Carbohydrates in particular. The extra gets sent to the liver, the liver turns it into triglycerides, and those get laid down over the organs.
The two tissues do not just sit in different places. They behave differently, and the behaviour of visceral fat is the whole problem.
Does cortisol cause belly fat, or does belly fat cause cortisol?
Both, and that is why it is such a trap. People say they have belly fat because they are stressed and their cortisol is high. It is a chicken-and-egg thing. Visceral fat carries far more cortisol receptors than the fat under your skin, and it has its own supply of an enzyme that converts cortisone, the inactive form, back into active cortisol inside the fat itself. So a perfectly normal amount of cortisol gets amplified in that tissue. It feels like too much cortisol even when your blood level is fine.
This is not a theory. In 2001 researchers engineered mice to make extra of that enzyme in their fat, at roughly the level found in obese humans, and the mice developed visceral obesity, insulin resistance and high blood fats, and ate more despite having plenty of the hormone that should have told them to stop. The belly fat was running the show. I have written about where that leads in cortisol face and in the signs of high cortisol in women; this post is about the fat itself.
Why is belly fat inflammatory?
Because it has to build its own blood supply. As a fat depot grows, the cells in the middle of it start to run short of oxygen. To fix that, the fat releases inflammatory signals, cytokines, whose job is to attract new blood vessels. The figure often quoted is that a pound of fat needs something like a mile of new capillaries. Those same signals are what show up on a blood test as high-sensitivity C-reactive protein. So visceral fat is not a passive store of energy. It is a gland, and what it secretes is inflammation and amplified cortisol.
What actually burns visceral fat?
Cut your carbohydrates, or your calories, and walk, long and slow. Visceral fat is the first fat you mobilise when you do, because of all the fat in your body it is the most metabolically active. A 2016 analysis of 117 studies and 4,815 people found that exercise tended to remove more visceral fat than dieting did, even though dieting took more weight off the scale. The two work on different things, and the walking works on the one you care about.
Two walks in particular. The first is in the morning, before you eat, when your body is already running on stored fat. The second is after your evening meal. Walking after a meal flattens the rise in blood sugar and the surge of insulin behind it; a 2022 review of the trials found that breaking up sitting with short bouts of light walking, including after meals, cut the rise in blood sugar by about 17 percent compared with sitting still. Both walks improve insulin resistance, both bring inflammation down, and both burn fat for energy. Long duration, low intensity. You do not need to run. One of the best things about having a dog is that this part takes care of itself.
The carbohydrate side matters because carbohydrate is the energy source that becomes visceral fat in the first place. Protein and fat at breakfast and lunch, carbohydrate from vegetables and fruit instead of bread, rice, pasta and chips, and the raw material for new belly fat stops arriving.
Why isn’t the scale moving?
Because fat does not weigh much, and you are keeping your muscle. If your waist is getting narrower and your clothes fit looser at the middle but the scale has not moved, that is a good sign. It is the opposite of failure. Burning a pound of belly fat while preserving your muscle might not change the number on the scale at all, and your health has dramatically improved.
If my shoulders fill out my shirt and my waist goes from 36 to 34, and I only lost a few pounds on the scale, that is a good outcome. That means I am preserving my muscle and getting rid of the belly fat.
So measure the right things. Your waist, with a tape. How your trousers fit. On blood work, fasting insulin and high-sensitivity CRP, which are the two numbers belly fat drives up and the two that come down as it goes. The scale measures water, muscle, bone and fat together and cannot tell you which one changed. The tape can.
References
- Masuzaki, H., Paterson, J., Shinyama, H., Morton, N. M., Mullins, J. J., Seckl, J. R., & Flier, J. S. (2001). A transgenic model of visceral obesity and the metabolic syndrome. Science, 294(5549), 2166–2170. https://doi.org/10.1126/science.1066285
- Verheggen, R. J., Maessen, M. F., Green, D. J., Hermus, A. R., Hopman, M. T., & Thijssen, D. H. (2016). A systematic review and meta-analysis on the effects of exercise training versus hypocaloric diet: distinct effects on body weight and visceral adipose tissue. Obesity Reviews, 17(8), 664–690. https://doi.org/10.1111/obr.12406
- Buffey, A. J., Herring, M. P., Langley, C. K., Donnelly, A. E., & Carson, B. P. (2022). The acute effects of interrupting prolonged sitting time in adults with standing and light-intensity walking on biomarkers of cardiometabolic health in adults: a systematic review and meta-analysis. Sports Medicine, 52(8), 1765–1787. https://doi.org/10.1007/s40279-022-01649-4
