About 70 percent of North American adults will suffer from type II diabetes or prediabetes. The most common cause of diabetes is excess fat in the liver, which prevents your body from responding to insulin to cause high blood sugar levels. When you have high blood sugar, the sugar can stick to and damage the outer membranes of cells, to increase risk for heart attacks, strokes, certain cancers, and dementia.
Exercise helps to prevent and treat diabetes by helping to remove fat from the liver so that the body can respond to insulin and prevent high rises in blood sugar. A review of fourteen studies that included 551 subjects, average age 53, found that a regular exercise program markedly reduced the amount of fat in the liver, even if the subjects did not lose any weight. Those who walked briskly were 3.5 times more likely to get rid of 30 percent of their liver fat than those were treated only with dietary changes. Liver fat was measured by MRIs, and the subjects walked briskly for 150 minutes per week (Am J Gastroenterol, Dec 23, 2022).
This study adds to an extensive list of other studies that show that exercise is an essential part of the treatment of diabetes, because it markedly reduces the amount of liver fat that can cause diabetes in the first place (Hepatol Commun, 2023 Mar 30;7(4):e0108). Both exercise and calorie restriction reduce liver fat in overweight and obese adults, but only exercise had a dose-dependent effect in reducing liver fat and reducing belly fat (Br J Spots Med, Jan 20, 2023).
Exercise helps to rid the liver of fat (J Med Internet Res, 2019 Jan 2;21(1):e11250; JMIR Form Res, 2021 Aug 17;5(8):e30239). Fatty liver is associated with a markedly increased risk for heart attacks (Clin Gastroenterol Hepatol, 2015 Aug;13(8):1513-20.e1), and obesity markedly increases risk for fatty liver disease (Curr Obes Rep, 2019 Sep;8(3):220-228).
How Does Excess Fat in the Liver Cause Diabetes?
Storing fat in your belly is a stronger risk factor for diabetes than just being overweight, and is arguably the most common cause of Type II diabetes in North America today (BMC Public Health, November 18, 2019). Most cases of Type II diabetes are caused by inability to respond to insulin because of excess fat in the liver (J Clin Invest, May 19, 2020). Having excess fat in your liver puts you at high risk for diabetes, strokes, heart attacks, certain cancers, liver failure and premature death. More than 50 percent of people with excess fat in their liver are already diabetic or prediabetic (J of Family Med and Prim Care, Dec, 2022;11(12):7640-7643), and 11-20 percent of people with excess fat in their liver will suffer from liver failure within 10–15 years (Clin Gastroenterol Hepatol, 2015;13:643–540). See my explanation of insulin resistance and fatty liver in How Sugar-Added Foods and Drinks Increase Risk for Heart Disease.
Use Both Aerobic Exercise and Resistance Exercise to Combat Insulin Resistance
• The larger your muscles, the less likely you are to become insulin resistant. A study done in mice suggests that high blood sugar will cause loss of muscle size (JCI Insight, February 21, 2019;4(4)).
• Six weeks of resistance exercise improves insulin sensitivity in young, overweight men (Experimental Physiology, Feb 1, 2019).
• A review of 105 studies showed that a regular exercise program lowers fasting blood sugar and HBA1c (which measures the amount of sugar stuck on hemoglobin) in both diabetics and non-diabetics, and that each additional 100 minutes per week of physical activity was associated with a mean average decrease of 2.75 mg/dL of fasting blood sugar (Acta Diabetol, (2017) 54:983).
• Strength training lowers high blood sugar levels and liver fat, even before weight loss occurs (Journal of Endocrinology, Apr 2019;241(1):59–70).
Getting Rid of Fat in Your Liver
There are no drugs to get fat out of your liver, but a fatty liver can often be cured with lifestyle changes. Just about everyone who has a big belly and small buttocks is already diabetic or pre-diabetic since genetically they preferentially store fat in their liver. To prevent fat from getting into your liver, you need to prevent blood sugar levels from rising too high after meals.
• Start and maintain a regular exercise program.
• Try to move about or exercise before or after you eat. Contracting muscles remove sugar from your bloodstream without needing insulin. See Move Around Before and After You Eat.LINK
• Lose excess fat, particularly in your belly. Ideally, you should be able to pinch less than an inch of fat under the skin on your belly.
• Base your diet on vegetables, fruits, whole grains, beans, nuts and other seeds. Severely restrict foods with added sugar and all sugared drinks including fruit juices, mammal meat, processed meats, and fried foods. If you have a large belly, you should also limit all refined carbohydrates such as those found in foods made from flour, including bakery products, pastas, and most dry breakfast cereals.
• Get blood levels of hydroxy vitamin D above 30 nmol/L
My Recommendations
Most cases of Type II diabetes are caused by insulin resistance which usually comes from excess fat in the liver and muscles. Both aerobic and resistance exercise help to prevent and treat diabetes by helping to empty the liver and muscles of excess sugar. Exercise helps to reduce excess weight, high blood pressure, high LDL cholesterol, and high triglycerides. Exercise also helps to increase healthy HDL cholesterol, strengthens muscles and bones, and combats depression. See Signs of a Fatty Liver
Caution: Exercise can cause a heart attack in a person who has blocked arteries or heart damage. Check with your doctor before you start a new exercise program or vigorous activity.
