For treatment of type II, dietary modification is the initial approach, but many patients require treatment with statins (HMG-CoA reductase inhibitors) to reduce cardiovascular risk. If the triglyceride level is markedly raised, fibrates (peroxisome proliferator-activated receptor-alpha agonists) may be preferable due to their beneficial effects. Combination treatment of statins and fibrates, while highly effective, causes a markedly increased risk of myopathy and rhabdomyolysis, so is only done under close supervision. Other agents commonly added to statins are ezetimibe, niacin, and bile acid sequestrants. Dietary supplementation with fish oil is also used to reduce elevated triglycerides, with the greatest effect occurring in patients with the greatest severity. Some evidence exists for benefit of plant sterol-containing products and omega-3 fatty acids.

FH is usually treated with statins. Statins act by inhibiting the enzyme hydroxymethylglutaryl CoA reductase (HMG-CoA-reductase) in the liver. In response, the liver produces more LDL receptors, which remove circulating LDL from the blood. Statins effectively lower cholesterol and LDL levels, although sometimes add-on therapy with other drugs is required, such as bile acid sequestrants (cholestyramine or colestipol), nicotinic acid preparations or fibrates. Control of other risk factors for cardiovascular disease is required, as risk remains somewhat elevated even when cholesterol levels are controlled. Professional guidelines recommend that the decision to treat a person with FH with statins should not be based on the usual risk prediction tools (such as those derived from the Framingham Heart Study), as they are likely to underestimate the risk of cardiovascular disease; unlike the rest of the population, FH have had high levels of cholesterol since birth, probably increasing their relative risk. Prior to the introduction of the statins, clofibrate (an older fibrate that often caused gallstones), probucol (especially in large xanthomas) and thyroxine were used to reduce LDL cholesterol levels.

More controversial is the addition of ezetimibe, which inhibits cholesterol absorption in the gut. While it reduces LDL cholesterol, it does not appear to improve a marker of atherosclerosis called the intima-media thickness. Whether this means that ezetimibe is of no overall benefit in FH is unknown.

There are no interventional studies that directly show mortality benefit of cholesterol lowering in FH. Rather, evidence of benefit is derived from a number of trials conducted in people who have polygenic hypercholesterolemia (in which heredity plays a smaller role). Still, a 1999 observational study of a large British registry showed that mortality in people with FH had started to improve in the early 1990s when statins were introduced.

A cohort study suggested that treatment of FH with statins leads to a 48% reduction in death from coronary heart disease to a point where people are no more likely to die of coronary heart disease than the general population. However, if the person already had coronary heart disease the reduction was 25%. The results emphasize the importance of early identification of FH and treatment with statins.

Alirocumab and evolocumab, both monoclonal antibodies against PCSK9, are specifically indicated as adjunct to diet and maximally tolerated statin therapy for the treatment of adults with heterozygous familial hypercholesterolemia, who require additional lowering of LDL cholesterol.

Homozygous FH is harder to treat. The LDL receptors are minimally functional, if at all. Only high doses of statins, often in combination with other medications, are modestly effective in improving lipid levels. If medical therapy is not successful at reducing cholesterol levels, LDL apheresis may be used; this filters LDL from the bloodstream in a process reminiscent of dialysis. Very severe cases may be considered for a liver transplant; this provides a liver with normally functional LDL receptors, and leads to rapid improvement of the cholesterol levels, but at the risk of complications from any solid organ transplant (such as rejection, infections, or side-effects of the medication required to suppress rejection). Other surgical techniques include partial ileal bypass surgery, in which part of the small bowel is bypassed to decrease the absorption of nutrients and hence cholesterol, and portacaval shunt surgery, in which the portal vein is connected to the vena cava to allow blood with nutrients from the intestine to bypass the liver.

Lomitapide, an inhibitor of the microsomal triglyceride transfer protein, was approved by the US FDA in December 2012 as an orphan drug for the treatment of homozygous familial hypercholesterolemia. In January 2013, The US FDA also approved mipomersen, which inhibits the action of the gene apolipoprotein B, for the treatment of homozygous familial hypercholesterolemia. Gene therapy is a possible future alternative.

The first line treatment is change of lifestyle (e.g., Dietary Guidelines for Americans and physical activity). However, if in three to six months of efforts at remedying risk factors prove insufficient, then drug treatment is frequently required. Generally, the individual disorders that compose the metabolic syndrome are treated separately. Diuretics and ACE inhibitors may be used to treat hypertension. Cholesterol drugs may be used to lower LDL cholesterol and triglyceride levels, if they are elevated, and to raise HDL levels if they are low. Use of drugs that decrease insulin resistance, e.g., metformin and thiazolidinediones, is controversial; this treatment is not approved by the U.S. Food and Drug Administration. Weight loss medications may result in weight loss. As obesity is often recognized as the culprit behind many of the additional symptoms, with weight loss and lifestyle changes in diet, physical activity, the need for other medications may diminish.

A 2003 study indicated cardiovascular exercise was therapeutic in approximately 31% of cases. The most probable benefit was to triglyceride levels, with 43% showing improvement; but fasting plasma glucose and insulin resistance of 91% of test subjects did not improve.

Many other studies have supported the value of physical activity and dietary modifications to treat metabolic syndrome. Some natural compounds, like ursolic acid, have been suggested as a treatment for obesity/metabolic syndrome based on the results of extensive research involving animal models; it is argued, however, that there is still a lack of data regarding the use of ursolic acid in humans, as phase-II/III trials of that drug have not been carried so far.

Restricting the overall dietary carbohydrate intake is more effective in reducing the most common symptoms of metabolic syndrome than the more commonly prescribed reduction in dietary fat intake.

The combination preparation simvastatin/sitagliptin (marketed as Juvisync) was introduced in 2011 and the use of this drug was to lower LDL levels and as well as increase insulin levels. This drug could have been used to treat metabolic syndrome but was removed from the market by Merck in 2013 due to business reasons.

High-dose statins, recommended to reduce cardiovascular risk, have been associated with higher progression to diabetes, particularly in patients with metabolic syndrome. The biological mechanisms are not entirely understood, however, the plausible explanation may lie in competitive inhibition of glucose transport via the solute carrier (SLC) family of transporters (specifically "SLCO1B1"), important in statin pharmacokinetics.

Some studies on mice suggest that a Time Restricted Diet (TRD) could be helpful in reversing obesity and possibly metabolic syndrome

Treatment is typically achieved via diet and exercise, although metformin may be used to reduce insulin levels in some patients (typically where obesity is present). A referral to a dietician is beneficial. Another method used to lower excessively high insulin levels is cinnamon as was demonstrated when supplemented in clinical human trials.

A low carbohydrate diet is particularly effective in reducing hyperinsulinism.

A healthy diet that is low in simple sugars and processed carbohydrates, and high in fiber, and vegetable protein is often recommended. This includes replacing white bread with whole-grain bread, reducing intake of foods composed primarily of starch such as potatoes, and increasing intake of legumes and green vegetables, particularly soy.

Regular monitoring of weight, blood sugar, and insulin are advised, as hyperinsulinemia may develop into diabetes mellitus type 2.

It has been shown in many studies that physical exercise improves insulin sensitivity. The mechanism of exercise on improving insulin sensitivity is not well understood however it is thought that exercise causes the glucose receptor GLUT4 to translocate to the membrane. As more GLUT4 receptors are present on the membrane more glucose is taken up into cells decreasing blood glucose levels which then causes decreased insulin secretion and some alleviation of hyperinsulinemia. Another proposed mechanism of improved insulin sensitivity by exercise is through AMPK activity. The beneficial effect of exercise on hyperinsulinemia was shown in a study by Solomon et al. (2009), where they found that improving fitness through exercise significantly decreases blood insulin concentrations.

The primary treatment for insulin resistance is exercise and weight loss. Research shows that a low-carbohydrate diet may help. Both metformin and thiazolidinediones improve insulin resistance, but only are approved therapies for type 2 diabetes, not for insulin resistance. By contrast, growth hormone replacement therapy may be associated with increased insulin resistance.

Metformin has become one of the more commonly prescribed medications for insulin resistance. Unfortunately, Metformin also masks Vitamin B12 deficiency, so accompanying sub-lingual Vitamin B12 tablets are recommended.

Insulin resistance is often associated with abnormalities in lipids particularly high blood triglycerides and low high density lipoprotein.

The "Diabetes Prevention Program" (DPP) showed that exercise and diet were nearly twice as effective as metformin at reducing the risk of progressing to type 2 diabetes. However, the participants in the DPP trial regained about 40% of the weight that they had lost at the end of 2.8 years, resulting in a similar incidence of diabetes development in both the lifestyle intervention and the control arms of the trial. One 2009 study found that carbohydrate deficit after exercise, but not energy deficit, contributed to insulin sensitivity increase.

Resistant starch from high-amylose corn, amylomaize, has been shown to reduce insulin resistance in healthy individuals, in individuals with insulin resistance, and in individuals with type 2 diabetes. Animal studies demonstrate that it cannot reverse damage already done by high glucose levels, but that it reduces insulin resistance and reduces the development of further damage.

Some types of polyunsaturated fatty acids (omega-3) may moderate the progression of insulin resistance into type 2 diabetes, however, omega-3 fatty acids appear to have limited ability to reverse insulin resistance, and they cease to be efficacious once type 2 diabetes is established.

Caffeine intake limits insulin action, but not enough to increase blood-sugar levels in healthy persons. People who already have type 2 diabetes may see a small increase in levels if they take 2 or 2-1/2 cups of coffee per day.

There is evidence that prediabetes is a curable disease state. Intensive weight loss and lifestyle intervention, if sustained, may improve glucose tolerance substantially and prevent progression from IGT to type 2 diabetes. The Diabetes Prevention Program (DPP) study found a 16% reduction in diabetes risk for every kilogram of weight loss. Reducing weight by 7% through a low-fat diet and performing 150 minutes of exercise a week is the goal. In observational studies, individuals following vegetarian diets are about half as likely to develop diabetes, compared with non-vegetarians. The ADA guidelines recommend modest weight loss (5–10% body weight), moderate-intensity exercise (30 minutes daily), and smoking cessation.

There are claims in the media that a high-fat, high-protein, low carbohydrates diet can reverse prediabetes, but scientific evidence is not conclusive as to whether this diet has any efficacy.

For patients with severe risk factors, prescription medication may be appropriate. This may be considered in patients for whom lifestyle therapy has failed, or is not sustainable, and who are at high-risk for developing type 2 diabetes. Metformin and acarbose help prevent the development of frank diabetes, and also have a good safety profile. Evidence also supports thiazolidinediones but there are safety concerns, and data on newer agents such as GLP-1 receptor agonists, DPP4 inhibitors or meglitinides are lacking.

Vitamin E supplements have shown to help children with the deficiency.

Testing the general population under the age of 40 without symptoms is of unclear benefit.

The American College of Endocrinology (ACE) and the American Association of Clinical Endocrinologists (AACE) have developed "lifestyle intervention" guidelines for preventing the onset of type 2 diabetes:

- Healthy meals (a diet with no saturated and trans fats, sugars, and refined carbohydrates, as well as limited the intake of sodium and total calories)

- Physical exercise (30–45 minutes of cardio vascular exercise per day, five days a week)

- Reducing weight by as little as 5–10 percent may have a significant impact on overall health

Various strategies have been proposed to prevent the development of metabolic syndrome. These include increased physical activity (such as walking 30 minutes every day), and a healthy, reduced calorie diet. Many studies support the value of a healthy lifestyle as above. However, one study stated these potentially beneficial measures are effective in only a minority of people, primarily due to a lack of compliance with lifestyle and diet changes. The International Obesity Taskforce states that interventions on a sociopolitical level are required to reduce development of the metabolic syndrome in populations.

The Caerphilly Heart Disease Study followed 2,375 male subjects over 20 years and suggested the daily intake of a pint (~568 ml) of milk or equivalent dairy products more than halved the risk of metabolic syndrome. Some subsequent studies support the authors' findings, while others dispute them. A systematic review of four randomized controlled trials found that a paleolithic nutritional pattern improved three of five measurable components of the metabolic syndrome in participants with at least one of the components.

Testing the general population under the age of 40 without symptoms is of unclear benefit.

Given the complicated nature of the "clamp" technique (and the potential dangers of hypoglycemia in some patients), alternatives have been sought to simplify the measurement of insulin resistance. The first was the Homeostatic Model Assessment (HOMA), and a more recent method is the Quantitative insulin sensitivity check index (QUICKI). Both employ fasting insulin and glucose levels to calculate insulin resistance, and both correlate reasonably with the results of clamping studies. Wallace "et al." point out that QUICKI is the logarithm of the value from one of the HOMA equations.

Diagnosis can be made by checking fasting and post prandial insulin levels either with normal meal or with 100gms of oral glucose

Dyslipidemia is an abnormal amount of lipids (e.g. triglycerides, cholesterol and/or fat phospholipids) in the blood. In developed countries, most dyslipidemias are hyperlipidemias; that is, an elevation of lipids in the blood. This is often due to diet and lifestyle. Prolonged elevation of insulin levels can also lead to dyslipidemia. Likewise, increased levels of O-GlcNAc transferase (OGT) may cause dyslipidemia.

Treatment of NAFLD typically involves counseling to improve nutrition and consequently body weight and composition. Diet changes have shown significant histological improvement. Specifically, avoiding food containing high-fructose corn syrup and trans-fats is recommended. A systematic review and meta-analysis found that omega-3 fatty acid supplementation in those with NAFLD/NASH using doses approaching or higher than 1 gram daily (median dose 4 grams/day with median duration 6 months treatment) has been associated with improvements in liver fat. The best dose of omega-3 fatty acids for individuals with NAFLD/NASH is unclear.

Epidemiological data have suggested that coffee consumption may be associated with a decreased incidence of NAFLD and may reduce the risk of liver fibrosis in those who already have NAFLD/NASH. Olive oil consumption, as part of the Mediterranean diet, is also a reasonable dietary intervention; the optimal dose of olive oil supplementation for people with NAFLD/NASH has not been well-established. Few studies have been performed to evaluate the respective impact of a diet rich in avocados, red wine, tree nuts, or tea in people with NAFLD/NASH. However, limited evidence suggests that avocados may improve other areas of cardiovascular health (i.e., lipid profile) and their addition to a balanced diet is reasonable. Red wine consumption (in modest amounts) is likely safe and may improve insulin resistance but definitive studies are lacking.

A permanent routine of exercise, eating healthily, and, during periods of being overweight, consuming the same number or fewer calories than used will prevent and help fight obesity. A single pound of fat yields approximately 3500 calories of energy (32 000 kJ energy per kilogram of fat), and weight loss is achieved by reducing energy intake, or increasing energy expenditure, thus achieving a negative balance. Adjunctive therapies which may be prescribed by a physician are orlistat or sibutramine, although the latter has been associated with increased cardiovascular events and strokes and has been withdrawn from the market in the United States, the UK, the EU, Australia, Canada, Hong Kong, Thailand, Egypt and Mexico.

A 2006 study published in the International Journal of Sport Nutrition and Exercise Metabolism, suggests that combining cardiovascular (aerobic) exercise with resistance training is more effective than cardiovascular training alone in getting rid of abdominal fat. An additional benefit to exercising is that it reduces stress and insulin levels, which reduce the presence of cortisol, a hormone that leads to more belly fat deposits.

Self-motivation by understanding the risks associated with abdominal obesity is widely regarded as being far more important than worries about cosmetics. In addition, understanding the health issues linked with abdominal obesity can help in the self-motivation process of losing the abdominal fat. As mentioned above, abdominal fat is linked with cardiovascular disease, diabetes, and cancer. Specifically it's the deepest layer of belly fat (the fat you cannot see or grab) that poses health risks, as these "visceral" fat cells produce hormones that can affect health (e.g. increased insulin resistance and/or breast cancer risk). The risk increases considering the fact that they are located in the proximity or in between organs in the abdominal cavity. For example, fat next to the liver drains into it, causing a fatty liver, which is a risk factor for insulin resistance, setting the stage for Type 2 diabetes.

In the presence of diabetes mellitus type 2, the physician might instead prescribe metformin and thiazolidinediones (rosiglitazone or pioglitazone) as antidiabetic drugs rather than sulfonylurea derivatives. Thiazolidinediones may cause slight weight gain but decrease "pathologic" abdominal fat (visceral fat), and therefore may be prescribed for diabetics with central obesity.

Thiazolidinedione has been associated with heart failure and increased cardiovascular risk; so it has been withdrawn from the market in Europe by EMA in 2010.

Low-fat diets may not be an effective long-term intervention for obesity: as Bacon and Aphramor wrote, "The majority of individuals regain virtually all of the weight that was lost during treatment." The Women's Health Initiative ("the largest and longest randomized, controlled dietary intervention clinical trial") found that long-term dietary intervention increased the waist circumference of both the intervention group and the control group, though the increase was smaller for the intervention group. The conclusion was that mean weight decreased significantly in the intervention group from baseline to year 1 by 2.2 kg (P<.001) and was 2.2 kg less than the control group change from baseline at year 1. This difference from baseline between control and intervention groups diminished over time, but a significant difference in weight was maintained through year 9, the end of the study.

Insulin sensitizers (metformin and thiazolidinediones) are commonly used for insulin resistance in those with NAFLD. Improvements in liver biochemistry and histology in patients with NAFLD through treatment with statins have been observed in numerous cases, although these studies were carried out on a relatively small sample of patients. Statins have also been recommended for use in treating dyslipidemia for patients with NAFLD. Treatment with pentoxifylline has demonstrated improvements in the histological appearance of fatty liver tissue under the microscope in many small trials.

Dunnigan-type familial partial lipodystrophy, also known as FPLD Type II and abbreviated as (FPLD2), is a rare monogenic form of insulin resistance characterized by loss of subcutaneous fat from the extremities, trunk, and gluteal region. FPLD recapitulates the main metabolic attributes of the insulin resistance syndrome, including central obesity, hyperinsulinemia, glucose intolerance and diabetes usually type 2, dyslipidemia, hypertension, and early endpoints of atherosclerosis. It can also result in hepatic steatosis. FPLD results from mutations in LMNA gene, which is the gene that encodes nuclear lamins A and C.

In the setting of critical illness, low cholesterol levels are predictive of clinical deterioration, and are correlated with altered cytokine levels.

In humans with genetic loss-of-function variants in one copy of the "ANGPTL3" gene, the serum LDL-C levels are reduced. In those with loss-of-function variants in both copies of "ANGPTL3", low LDL-C, low HDL-C, and low triglycerides are seen ("familial combined hypolipidemia").

Hooft disease is a rare condition evidenced by low blood lipid level, red rash and mental and physical retardation.

Cilostazol or pentoxifylline can improve symptoms in some. Cilostazol may improve walking distance for people who experience claudication due to peripheral artery disease, but there is no strong evidence to suggest that it improves the quality of life, decreases mortality, or decreases the risk of cardiovascular events.

Treatment with other drugs or vitamins are unsupported by clinical evidence, "but trials evaluating the effect of folate and vitamin B-12 on hyperhomocysteinemia, a putative vascular risk factor, are near completion".

There are numerous theories as to the exact cause and mechanism in Type 2 Diabetes. Central obesity is known to predispose individuals for insulin resistance. Abdominal fat is especially active hormonally, secreting a group of hormones called adipokines that may possibly impair glucose tolerance. But adiponectin which is found in lower concentration in obese and diabetic individuals has shown to be beneficial and protective in Type 2 diabetes mellitus.

Insulin resistance is a major feature of Diabetes Mellitus Type 2 (T2DM), and central obesity is correlated with both insulin resistance and T2DM itself. Increased adiposity (obesity) raises serum resistin levels, which in turn directly correlate to insulin resistance. Studies have also confirmed a direct correlation between resistin levels and T2DM. And it is waistline adipose tissue (central obesity) which seems to be the foremost type of fat deposits contributing to rising levels of serum resistin. Conversely, serum resistin levels have been found to "decline" with decreased adiposity following medical treatment.

The treatment of fatty liver depends on its cause, and, in general, treating the underlying cause will reverse the process of steatosis if implemented at an early stage. Two known causes of fatty liver disease are an excess consumption of alcohol and a prolonged diet containing foods with a high proportion of calories coming from lipids. For the patients with non-alcoholic fatty liver disease with pure steatosis and no evidence of inflammation, a gradual weight loss is often the only recommendation. In more serious cases, medications that decrease insulin resistance, hyperlipidemia, and those that induce weight loss have been shown to improve liver function.

For advanced patients with non-alcoholic steatohepatitis (NASH), there are no currently available therapies.

Up to 10% of people with cirrhotic alcoholic FLD will develop hepatocellular carcinoma. The overall incidence of liver cancer in nonalcoholic FLD has not yet been quantified, but the association is well-established.

Bariatric surgery, while not currently recommended as a treatment for fatty liver disease (FLD) alone, has been shown to revert FLD and advanced steatohepatitis in over 90% of people who have undergone this surgery for the treatment of obesity.

After a trial of the best medical treatment outline above, if symptoms persist, patients may be referred to a vascular or endovascular surgeon. The benefit of revascularization is thought to correspond to the severity of ischemia and the presence of other risk factors for limb loss such as wound and infection severity.

- Angioplasty (PTA, or percutaneous transluminal angioplasty) can be done on solitary lesions in large arteries, such as the femoral artery, but angioplasty may not have sustained benefits. Patency rates following angioplasty are highest for iliac arteries, and decrease with arteries towards the toes. Other criteria that affect outcome following revascularization are length of lesion, and number of lesions. There does not appear to be long term advantages or sustained benefit to placing a stent following angioplasty in order to hold the narrowing of the superficial femoral artery open.

- Atherectomy, in which the plaque is scraped off of the inside of the vessel wall (albeit with no better results than angioplasty).

- Vascular bypass grafting can be performed to circumvent a diseased area of the arterial vasculature. The great saphenous vein is used as a conduit if available, although artificial (Gore-Tex or PTFE) material is often used for long grafts when adequate venous conduit is unavailable.

- When gangrene has set in, amputation is required to prevent infected tissues from causing sepsis a life-threatening illness.

- Thrombolysis and thrombectomy are used in cases of arterial thrombosis or embolism.

A 2017 review concluded that while both myo-inositol and D-chiro-inositols may regulate menstrual cycles and improve ovulation, there is a lack of evidence regarding effects on the probability of pregnancy. A 2012 and 2017 review have found myo-inositol supplementation appears to be effective in improving several of the hormonal disturbances of PCOS. A 2011 review found not enough evidence to conclude any beneficial effect from D-chiro-inositol. There is insufficient evidence to support the use of acupuncture.