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.

The progression to type 2 diabetes mellitus is not inevitable for those with prediabetes. The progression into diabetes mellitus from prediabetes is approximately 25% over three to five years.

Some research has suggested breastfeeding decreases the risk in later life and early introduction of gluten-containing cereals in the diet increases the risk of developing islet cell autoantibodies; various other nutritional risk factors are being studied, but no firm evidence has been found.

Giving children 2000 IU of vitamin D daily during their first year of life is associated with reduced risk of type 1 diabetes, though the causal relationship is obscure.

Children with antibodies to beta cell proteins (i.e. at early stages of an immune reaction to them) but no overt diabetes, and treated with niacinamide (vitamin B), had less than half the diabetes onset incidence in a seven-year time span than did the general population, and an even lower incidence relative to those with antibodies as above, but who received no niacinamide.

People with type 1 diabetes and undiagnosed celiac disease have worse glycaemic control and a higher prevalence of nephropathy and retinopathy. Gluten-free diet, when performed strictly, improves diabetes symptoms and appears to have a protective effect against developing long-term complications. Nevertheless, dietary management of both these diseases is challenging and these patients have poor compliance of the diet.

Onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular exercise. Intensive lifestyle measures may reduce the risk by over half. The benefit of exercise occurs regardless of the person's initial weight or subsequent weight loss. High levels of physical activity reduce the risk of diabetes by about 28%. Evidence for the benefit of dietary changes alone, however, is limited, with some evidence for a diet high in green leafy vegetables and some for limiting the intake of sugary drinks. In those with impaired glucose tolerance, diet and exercise either alone or in combination with metformin or acarbose may decrease the risk of developing diabetes. Lifestyle interventions are more effective than metformin. A 2017 review found that, long term, lifestyle changes decreased the risk by 28%, while medication does not reduce risk after withdrawal. While low vitamin D levels are associated with an increased risk of diabetes, correcting the levels by supplementing vitamin D3 does not improve that risk.

Cyclosporine A, an immunosuppressive agent, has apparently halted destruction of beta cells (on the basis of reduced insulin usage), but its kidney toxicity and other side effects make it highly inappropriate for long-term use.

Anti-CD3 antibodies, including teplizumab and otelixizumab, had suggested evidence of preserving insulin production (as evidenced by sustained C-peptide production) in newly diagnosed type 1 diabetes patients. A probable mechanism of this effect was believed to be preservation of regulatory T cells that suppress activation of the immune system and thereby maintain immune system homeostasis and tolerance to self-antigens. The duration of the effect is still unknown, however. In 2011, Phase III studies with otelixizumab and teplizumab both failed to show clinical efficacy, potentially due to an insufficient dosing schedule.

An anti-CD20 antibody, rituximab, inhibits B cells and has been shown to provoke C-peptide responses three months after diagnosis of type 1 diabetes, but long-term effects of this have not been reported.

A proper diet and exercise are the foundations of diabetic care, with a greater amount of exercise yielding better results. Aerobic exercise leads to a decrease in HbA and improved insulin sensitivity. Resistance training is also useful and the combination of both types of exercise may be most effective. A diabetic diet that promotes weight loss is important. While the best diet type to achieve this is controversial, a low glycemic index diet or low carbohydrate diet has been found to improve blood sugar control. Culturally appropriate education may help people with type 2 diabetes control their blood sugar levels, for up to 24 months. If changes in lifestyle in those with mild diabetes has not resulted in improved blood sugars within six weeks, medications should then be considered. There is not enough evidence to determine if lifestyle interventions affect mortality in those who already have DM2. Vegetarian diets in general have been related to lower diabetes risk, but do not offer advantages compared with diets which allow moderate amounts of animal products. There is not enough evidence to suggest that cinnamon improves blood sugar levels in people with type 2 diabetes.

Too much insulin may result in a contradictory increase of blood glucose. This "Somogyi effect" is often noted by cat owners who monitor their cat's blood glucose at home. Anytime the blood glucose level drops too far to hypoglycemia, the body may defensively dump glucose (converted from glycogen in the liver), as well as hormones epinephrine and cortisol, into the bloodstream. The glycogen raises the blood glucose, while the other hormones may make the cat insulin-resistant for a time. If the body has no glycogen reserves, there will be no rebound effect and the cat will just be hypoglycemic.

Even a small overdose can trigger a rebound effect (A typical case is increasing bidaily dosage from 1 unit to 2, passing a correct dose of 1.5 units.)

Rebound hyperglycemia occurs rarely in cats treated with glargine in a protocol aiming for tight control of blood glucose concentrations.

There is no known preventive measure for type 1 diabetes. Type 2 diabeteswhich accounts for 85–90% of all casescan often be prevented or delayed by maintaining a normal body weight, engaging in physical activity, and consuming a healthy diet. Higher levels of physical activity (more than 90 minutes per day) reduce the risk of diabetes by 28%. Dietary changes known to be effective in helping to prevent diabetes include maintaining a diet rich in whole grains and fiber, and choosing good fats, such as the polyunsaturated fats found in nuts, vegetable oils, and fish. Limiting sugary beverages and eating less red meat and other sources of saturated fat can also help prevent diabetes. Tobacco smoking is also associated with an increased risk of diabetes and its complications, so smoking cessation can be an important preventive measure as well.

The relationship between type 2 diabetes and the main modifiable risk factors (excess weight, unhealthy diet, physical inactivity and tobacco use) is similar in all regions of the world. There is growing evidence that the underlying determinants of diabetes are a reflection of the major forces driving social, economic and cultural change: globalization, urbanization, population aging, and the general health policy environment.

The method usually employed is a dose of slow-acting insulin, twice daily, to keep the blood sugar within a recommended range for the entire day. With this method, it is important for the cat to avoid large meals or high-carbohydrate food. Meals may also be timed to coincide with peak insulin activity. Once-daily doses are not recommended, since insulin usually metabolizes faster in cats than in humans or dogs. For example, an insulin brand that lasts 24 hours in people may only be effective for about 12 in a cat.

Cats may be treated with animal insulin (bovine-based insulin is most similar to cat insulin), or with human synthetic insulin. The best choice of insulin brand and type varies from animal-to-animal and may require some trial-and-error. The human synthetic insulin, Humulin N /Novolin N/ NPH, is usually a poor choice for cats, since cats metabolize insulin about twice as fast. The Lente and Ultralente versions were popular for feline use until summer 2005, when they were discontinued.

Until the early 1990s, the most recommended type for pets was bovine/porcine-derived PZI, but that type was phased out over the 1990s and is now difficult to find in many countries. There are sources in the US and UK, and many vets are now starting to recommend them again for pets, but they have been discontinued by most manufacturers as of 2007-2008. A new synthetic PZI analogue called ProZinc is now available.

Caninsulin (known in the USA as Vetsulin) is a brand of porcine-based insulin approved for cats which is available with a veterinarian's prescription. According to the manufacturer's website, the insulin's action profile in cats was similar to that of NPH insulin, and lowered blood sugar quickly, but for only about 6–8 hours. Vetsulin was recalled in the USA in November 2009 due to inconsistent strength; it was available again as of April 2013.

Two ultra-slow time-release synthetic human insulins became available in 2004 and 2005, generically known as insulin detemir (Levemir) and insulin glargine (Lantus). Studies have had good results with insulin glargine in cats. Follow-up research shows that Levemir can be used with a similar protocol and that either insulin, on this protocol, can lead uncomplicated feline cases to remission, with the most success being in cats who start on these protocols as soon as possible after diagnosis.

The general form of this treatment is an intermediate-acting basal insulin with a regimen of food and insulin every 12 hours, with the insulin injection following the meal. The most commonly used intermediate-acting insulins are NPH, also referred to as isophane, or Caninsulin, also known as Vetsulin, a porcine Lente insulin. While the normal diabetes routine is timed feedings with insulin shots following the meals, dogs unwilling to adhere to this pattern can still attain satisfactory regulation. Most dogs do not require basal/bolus insulin injections; treatment protocol regarding consistency in the diet's calories and composition along with the established feeding and injection times is generally a suitable match for the chosen intermediate-acting insulin.

With Lantus and protamine zinc insulin (PZI) being unreliable in dogs, they are rarely used to treat canine diabetes. Bovine insulin has been used as treatment for some dogs, particularly in the UK. Pfizer Animal Health discontinued of all three types of its veterinary Insuvet bovine insulins in late 2010 and suggested patients be transitioned to Caninsulin. The original owner of the insulin brand, Schering-Plough Animal Health, contracted Wockhardt UK to produce them. Wockhardt UK has produced both bovine and porcine insulins for the human pharmaceutical market for some time.

Diabetes mellitus is a chronic disease, for which there is no known cure except in very specific situations. Management concentrates on keeping blood sugar levels as close to normal, without causing low blood sugar. This can usually be accomplished with a healthy diet, exercise, weight loss, and use of appropriate medications (insulin in the case of type 1 diabetes; oral medications, as well as possibly insulin, in type 2 diabetes).

Learning about the disease and actively participating in the treatment is important, since complications are far less common and less severe in people who have well-managed blood sugar levels. The goal of treatment is an HbA level of 6.5%, but should not be lower than that, and may be set higher. Attention is also paid to other health problems that may accelerate the negative effects of diabetes. These include smoking, elevated cholesterol levels, obesity, high blood pressure, and lack of regular exercise. Specialized footwear is widely used to reduce the risk of ulceration, or re-ulceration, in at-risk diabetic feet. Evidence for the efficacy of this remains equivocal, however.

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.

Most of the commercially available prescription diabetes foods are high in fiber, complex carbohydrates, and have proven therapeutic results. Of primary concern is getting or keeping the animal eating, as use of the prescribed amount of insulin is dependent on eating full meals. When no meal is eaten, there is still a need for a basal dosage of insulin, which supplies the body's needs without taking food into consideration. Eating a partial meal means a reduction in insulin dose. Basal and reduced insulin dose information should be part of initial doctor–client diabetes discussions in case of need.

It is possible to regulate diabetes without any diet change. If the animal will not eat a prescribed diet, it is not in the dog's best interest to insist on it; the amount of additional insulin required because a non-prescription diet is being fed is generally between 2–4%. Semi moist foods should be avoided as they tend to contain a lot of sugars. Since dogs with diabetes are prone to pancreatitis and hyperlipidemia, feeding a low-fat food may help limit or avoid these complications. A non-prescription food with a "fixed formula" would be suitable because of the consistency of its preparation. Fixed formula foods contain precise amounts of their ingredients so batches or lots do not vary much if at all. "Open formula" foods contain the ingredients shown on the label but the amount of them can vary, however they must meet the guaranteed analysis on the package. These changes may have an effect on the control of diabetes. Prescription foods are fixed formulas, while most non-prescription ones are open formula unless the manufacturer states otherwise.

About 80% of all LADA patients initially misdiagnosed with type 2 (and who have GAD antibodies) will become insulin-dependent within 3 to 15 years (according to differing LADA sources).

The treatment for Type 1 diabetes/LADA is exogenous insulin to control glucose levels, prevent further destruction of residual beta cells, reduce the possibility of diabetic complications, and prevent death from diabetic ketoacidosis (DKA). Although LADA may appear to initially respond to similar treatment (lifestyle and medications) as type 2 diabetes, it will not halt or slow the progression of beta cell destruction, and people with LADA will eventually become insulin-dependent. People with LADA have insulin resistance similar to long-term type 1 diabetes; some studies showed that people with LADA have less insulin resistance, compared with those with type 2 diabetes; however, others have not found a difference.

In some forms of MODY, standard treatment is appropriate, though exceptions occur:

- In MODY2, oral agents are relatively ineffective and insulin is unnecessary.

- In MODY1 and MODY3, insulin may be more effective than drugs to increase insulin sensitivity.

- Sulfonylureas are effective in the K channel forms of neonatal-onset diabetes. The mouse model of MODY diabetes suggested that the reduced clearance of sulfonylureas stands behind their therapeutic success in human MODY patients, but Urbanova et al. found that human MODY patients respond differently to the mouse model and that there was no consistent decrease in the clearance of sulfonylureas in randomly selected HNF1A-MODY and HNF4A-MODY patients.

Modulating and ameliorating diabetic complications may improve the overall quality of life for diabetic patients. For example; when elevated blood pressure was tightly controlled, diabetic related deaths were reduced by 32% compared to those with less controlled blood pressure.

The risk of progression to diabetes and development of cardiovascular disease is greater than for impaired fasting glucose.

Although some drugs can delay the onset of diabetes, lifestyle modifications play a greater role in the prevention of diabetes. Patients identified as having an IGT may be able to prevent diabetes through a combination of increased exercise and reduction of body weight. "Drug therapy can be considered when aggressive lifestyle interventions are unsuccessful."

Clinical Trials of NDM

- The research article is entitled, "A Successful Transition to sulfonamides treatment in male infant with novel neonatal diabetes mellitus (NDM) caused by the ABBC8 gene mutation and 3 years follow up". It is a case study on the transitioning of treatments from insulin therapy to sulfonamides therapy. NDM is not initiated by an autoimmune mechanism but mutations in K-sensitve channel, "KCNJ11, ABCC8" and "INS" genes are successful targets for changing treatments from insulin to sulfonamides therapy.

- Introduction: Within this study a two month old male was admitted into the intensive care unit, because the he was showing signs of diabetic ketoacidosis. Other symptoms include, respiratory tract infection, sporous, dehydration, reduced subcutaneous fat, Candida mucous infection. The infant's family history was negative for diseases of importance to hereditary and the eldest sibling was healthy.

- Experiment: The current treatment plan consist of therapy for ketoacidosis was started upon admissions into the hospital. Also, subcutaneous insulin was given (0.025-0.05 units/kg/h) and adjusted to the glycaemic profiles and the patient was converted to euglycaemic state. After 24 hours, oral intake of insulin started and treatment continued with subcutaneous short acting insulin then intermediate acting insulin plus 2 dosage of short acting insulin. A genetic analysis was conducted for NDM and mutation of KCNJ11, "ABCC8" and "INS" genes have been given. Sequence analysis showed a rare heterogeneous missense mutation, PF577L, in the patient's exon 12 of ABCC8 gene. This confirms diagnosis of NDM caused by heterozygous mutation in the SUR1 subunit of the pancreatic ATP-sensitive potassium channel, because his parents' white blood cells did not show signs of this mutation.

- Results: Switching from the insulin therapy to the sulfonamides was a successful treatment. It is the current regimen used to treat NDM.

- Discussion/Conclusion: ABCC8 gene produces SUR1 protein subunit that interacts with pancreatic ATP-sensitive potassium channel. When the channel opens a large amount of insulin is released. Mutations that occur in ABCC8 are associated with congential hyperinsulinism and PNDM or TNDM. Patients that have mutations in their potassium channel, improved their glucose levels with sulfonylurea regimen and glibenclamide showed successful results in managing glucose levels as well.

- A 2006 study showed that 90% of patients with a KCNJ11 mutation were able to successfully transition to sulfonylurea therapy.

A 1988 study over 41 months found that improved glucose control led to initial "worsening of complications" but was not followed by the expected improvement in complications. In 1993 it was discovered that the serum of diabetics with neuropathy is toxic to nerves, even if its blood sugar content is normal.

Research from 1995 also challenged the theory of hyperglycemia as the cause of diabetic complications. The fact that 40% of diabetics who carefully controlled their blood sugar nevertheless developed neuropathy made clear other factors were involved.

In a 2013 meta-analysis of 6 randomized controlled trials involving 27,654 patients, tight blood glucose control reduced the risk for some macrovascular and microvascular events but without effect on all-cause mortality and cardiovascular mortality.

Chronic hyperglycemia due to any cause can eventually cause blood vessel damage and the microvascular complications of diabetes. The principal treatment goals for people with MODY — keeping the blood sugars as close to normal as possible ("good glycemic control"), while minimizing other vascular risk factors — are the same for all known forms of diabetes.

The tools for management are similar for all forms of diabetes: blood testing, changes in diet, physical exercise, oral hypoglycemic agents, and insulin injections. In many cases these goals can be achieved more easily with MODY than with ordinary types 1 and 2 diabetes. Some people with MODY may require insulin injections to achieve the same glycemic control that another person may attain with careful eating or an oral medication.

When oral hypoglycemic agents are used in MODY, the sulfonylureas remain the oral medication of first resort. When compared to patients with type 2 diabetes, MODY patients are often more sensitive to sulphonylureas, such that a lower dose should be used to initiate treatment to avoid hypoglycaemia. Patients with MODY less often suffer from obesity and insulin resistance than those with ordinary type 2 diabetes (for whom insulin sensitizers like metformin or the thiazolidinediones are often preferred over the sulfonylureas).

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 guidelines for preventing impaired fasting glucose are the same as those given for preventing type 2 diabetes in general. If these are adhered to, the progression to clinical diabetes can be slowed or halted. In some cases, a complete reversal of IFG can be achieved. Certain risk factors, such as being of Afro-Caribbean or South Asian ethnicity, as well as increasing age, are unavoidable, and such individuals may be advised to follow these guidelines, as well as monitor their blood glucose levels, more closely.

There are no known ways of preventing LADA type 1 diabetes, though some researchers believe it could be stopped at a very early stage if a diagnosis is made prior to the body's destruction of its beta cells.

Counselling before pregnancy (for example, about preventive folic acid supplements) and multidisciplinary management are important for good pregnancy outcomes. Most women can manage their GDM with dietary changes and exercise. Self monitoring of blood glucose levels can guide therapy. Some women will need antidiabetic drugs, most commonly insulin therapy.

Any diet needs to provide sufficient calories for pregnancy, typically 2,000 – 2,500 kcal with the exclusion of simple carbohydrates. The main goal of dietary modifications is to avoid peaks in blood sugar levels. This can be done by spreading carbohydrate intake over meals and snacks throughout the day, and using slow-release carbohydrate sources—known as the G.I. Diet. Since insulin resistance is highest in mornings, breakfast carbohydrates need to be restricted more. Ingesting more fiber in foods with whole grains, or fruit and vegetables can also reduce the risk of gestational diabetes.

Regular moderately intense physical exercise is advised, although there is no consensus on the specific structure of exercise programs for GDM.

Self monitoring can be accomplished using a handheld capillary glucose dosage system. Compliance with these glucometer systems can be low. Target ranges advised by the Australasian Diabetes in Pregnancy Society are as follows:

- fasting capillary blood glucose levels <5.5 mmol/L

- 1 hour postprandial capillary blood glucose levels <8.0 mmol/L

- 2 hour postprandial blood glucose levels <6.7 mmol/L

Regular blood samples can be used to determine HbA1c levels, which give an idea of glucose control over a longer time period.

Research suggests a possible benefit of breastfeeding to reduce the risk of diabetes and related risks for both mother and child.

Treatment of GDM with diet and insulin reduces health problems mother and child. Treatment of GDM is also accompanied by more inductions of labour.

A repeat OGTT should be carried out 6 weeks after delivery, to confirm the diabetes has disappeared. Afterwards, regular screening for type 2 diabetes is advised.

If a diabetic diet or G.I. Diet, exercise, and oral medication are inadequate to control glucose levels, insulin therapy may become necessary.

The development of macrosomia can be evaluated during pregnancy by using sonography. Women who use insulin, with a history of stillbirth, or with hypertension are managed like women with overt diabetes.