Diabetes and Lifestyle: Understanding and Managing Type 1 and Type 2 Diabetes

Diabetes is one of the fastest-growing chronic diseases in the world. According to the WHO, more than 800 million adults globally now live with diabetes – a number that has quadrupled since 1990. The disease affects how the body processes blood glucose (sugar), and if left unmanaged, it can lead to severe damage to the heart, kidneys, eyes, and nerves. The rise is largely driven by lifestyle factors: poor diet, physical inactivity, and increasing rates of obesity. Understanding the types of diabetes, what causes them, and how to prevent or manage the condition is essential – not just for patients, but for anyone looking to lead a healthier life.

What is diabetes? 🔗

Diabetes mellitus is a chronic metabolic disorder characterized by persistently high blood glucose levels. It occurs when the pancreas either does not produce enough of the hormone insulin, or when the body cannot effectively use the insulin it produces. Insulin is crucial because it helps move glucose from the bloodstream into cells, where it is used for energy. When this process fails, glucose accumulates in the blood, a condition known as hyperglycemia. Over time, sustained hyperglycemia damages blood vessels, nerves, and multiple organ systems throughout the body.

The two most common forms are Type 1 diabetes and Type 2 diabetes. While they share the hallmark of elevated blood sugar, their causes, onset patterns, and management approaches differ significantly. A third form, gestational diabetes, develops during pregnancy and typically resolves after delivery, though it increases the mother’s long-term risk of developing Type 2 diabetes.

Types and causes of diabetes 🔗

Type 1 diabetes 🔗

Type 1 diabetes is an autoimmune condition in which the body’s immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. This results in little to no insulin production, making daily insulin administration essential for survival. The WHO reports that approximately 9 million people worldwide had Type 1 diabetes as of 2017, with the majority living in high-income countries.

Type 1 diabetes typically develops in childhood or adolescence, which is why it was previously known as “juvenile diabetes.” However, it can appear at any age. The exact trigger for the autoimmune response remains unclear, though researchers believe a combination of genetic predisposition and environmental factors – such as viral infections – may play a role. Importantly, Type 1 diabetes cannot be prevented through lifestyle changes. It is not caused by diet or physical inactivity.

Common symptoms include excessive thirst, frequent urination, unexplained weight loss, constant hunger, fatigue, and blurred vision. These symptoms often appear suddenly and can escalate quickly, making early diagnosis critical.

Type 2 diabetes 🔗

Type 2 diabetes is by far the more prevalent form, accounting for over 90% of all diabetes cases. Unlike Type 1, the pancreas still produces insulin in Type 2 diabetes, but the body’s cells become resistant to its effects – a condition called insulin resistance. Over time, the pancreas cannot keep up with the increased demand, and blood sugar levels rise.

The primary risk factors for Type 2 diabetes are closely tied to lifestyle:

Excess body weight and obesity: Being overweight, especially carrying excess fat around the abdomen, significantly increases insulin resistance. Obesity is the single most important modifiable risk factor for Type 2 diabetes.

Physical inactivity: A sedentary lifestyle reduces the body’s ability to use insulin efficiently. Lack of regular movement contributes to weight gain and worsens metabolic health.

Unhealthy diet: Diets high in processed foods, refined sugars, and unhealthy fats contribute to obesity and metabolic dysfunction. The adoption of calorie-dense, nutrient-poor diets – sometimes referred to as “Westernized” dietary patterns – has been linked to rising diabetes rates globally.

Genetics and family history: Having a parent or sibling with Type 2 diabetes increases risk. Certain ethnic groups, including South Asian, African, Hispanic, and Pacific Islander populations, face higher genetic susceptibility.

Age: Risk increases with age, particularly after 45. However, Type 2 diabetes is increasingly being diagnosed in younger people and even children, driven by rising childhood obesity rates.

Symptoms of Type 2 diabetes are often mild and develop gradually, which means the disease can go undetected for years. PAHO/WHO notes that the disease may be diagnosed several years after onset, by which time complications may have already developed. This is why regular screening is important, especially for individuals with known risk factors.

Prediabetes: the warning stage 🔗

Before full-blown Type 2 diabetes develops, most individuals pass through a stage called prediabetes. This is characterized by blood sugar levels that are higher than normal but not yet high enough to be classified as diabetes. Two conditions fall under prediabetes: impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). People in this stage are at high risk of progressing to Type 2 diabetes, but progression is not inevitable. Lifestyle changes at this stage can be highly effective in reversing the trajectory.

Prevention and management strategies 🔗

Primary prevention: stopping Type 2 diabetes before it starts 🔗

Primary prevention aims to reduce the risk of developing diabetes in the first place. Since Type 1 diabetes currently cannot be prevented, primary prevention efforts focus on Type 2 diabetes. The evidence here is strong and encouraging.

The landmark Diabetes Prevention Program (DPP) – a major clinical trial funded by the U.S. National Institutes of Health – demonstrated that participants who adopted modest lifestyle changes reduced their risk of developing Type 2 diabetes by 58% compared to a placebo group. The two core goals were straightforward: achieve a 7% reduction in body weight and engage in at least 150 minutes of moderate physical activity per week (such as brisk walking). Follow-up studies showed that these benefits persisted for at least 15 years.

Based on this and similar research from Finland and China, the key pillars of primary prevention include:

Maintaining a healthy body weight: Even modest weight loss – 5% to 7% of body weight – can dramatically reduce diabetes risk in high-risk individuals.

Regular physical activity: At least 150 minutes per week of moderate-intensity exercise. According to NIH’s Endotext resource, exercise is a cornerstone of both diabetes prevention and treatment, with well-documented benefits for insulin sensitivity, cardiovascular health, and blood glucose control.

Eating a balanced diet: Emphasizing whole grains, vegetables, fruits, lean proteins, and healthy fats while limiting processed foods, sugary drinks, and excessive carbohydrate intake.

Avoiding tobacco use: Smoking is associated with increased diabetes risk and accelerates the development of vascular complications in those who already have the disease.

Secondary prevention: early detection and management 🔗

Secondary prevention focuses on catching diabetes early and managing it effectively to prevent complications. Since Type 2 diabetes can remain asymptomatic for years, regular screening through blood glucose tests is critical, particularly for people over 45, those with a family history, or individuals who are overweight.

Common diagnostic tests include the fasting blood glucose test, the oral glucose tolerance test (OGTT), and the HbA1c test, which measures average blood sugar levels over the previous two to three months. Early diagnosis allows for timely intervention and significantly improves outcomes.

Managing diabetes: diet, exercise, and medication 🔗

For those already living with diabetes, management requires a combination of lifestyle changes and, in many cases, medical treatment.

Dietary management: Medical nutrition therapy is fundamental. Research published in the Journal of Diabetes Investigation shows that appropriate dietary adjustments can reduce HbA1c levels by 0.3% to 2.0% in people with Type 2 diabetes. Individual nutrition plans should consider age, body weight, existing complications, cultural food preferences, and access to healthy food options. The goal is to maintain stable blood glucose levels while meeting nutritional needs.

Exercise: Physical activity improves insulin sensitivity and helps control blood glucose levels. Studies have demonstrated that an exercise intervention of at least eight weeks can produce a meaningful average reduction in HbA1c levels. Both aerobic exercise (walking, swimming, cycling) and resistance training are beneficial. The American Diabetes Association’s 2025 Standards of Care recommend regular physical activity as an integral component of diabetes treatment plans.

Medications: People with Type 1 diabetes require daily insulin injections or an insulin pump to survive. For Type 2 diabetes, treatment may begin with oral medications such as metformin, which helps the body use insulin more effectively. As the disease progresses, some individuals may also need insulin or newer classes of medications such as GLP-1 receptor agonists and SGLT2 inhibitors. Blood pressure and cholesterol-lowering medications are often prescribed alongside diabetes drugs to reduce cardiovascular risk.

Self-monitoring: Regular blood glucose monitoring – through traditional glucose meters or continuous glucose monitoring (CGM) devices – helps individuals track their levels and adjust diet, activity, and medication accordingly.

Long-term complications of diabetes 🔗

When diabetes is poorly controlled over a prolonged period, chronically elevated blood sugar damages blood vessels and nerves throughout the body. Complications are broadly divided into microvascular (affecting small blood vessels in the eyes, kidneys, and nerves) and macrovascular (affecting larger blood vessels, leading to heart disease and stroke).

Diabetic retinopathy (eye damage) 🔗

Diabetic retinopathy is one of the most common complications and a leading cause of preventable blindness among working-age adults. High blood sugar levels gradually damage the tiny blood vessels in the retina. According to the Merck Manual, retinopathy is characterized initially by small bulges in the blood vessel walls (microaneurysms) and can progress to abnormal new blood vessel growth (proliferative retinopathy) and swelling of the macula. In the early stages, there may be no symptoms at all. As the condition advances, individuals may experience blurred vision, dark spots, and eventually complete vision loss. Annual eye examinations are recommended for all people with diabetes to catch retinopathy early, when treatment such as laser therapy or injections can preserve vision.

Diabetic nephropathy (kidney disease) 🔗

The kidneys filter waste products and excess fluid from the blood. Chronic hyperglycemia damages the delicate filtering units (glomeruli) within the kidneys, gradually reducing their function. Diabetic nephropathy develops in 20% to 40% of adults with diabetes and is a leading cause of end-stage kidney disease requiring dialysis or transplantation. The American Heart Association notes that kidney damage from diabetes progresses slowly and can eventually lead to kidneys ceasing to function effectively. Early detection through regular urine albumin testing is crucial, as treatment with blood pressure medications (particularly ACE inhibitors or ARBs) and strict blood sugar control can significantly slow progression.

Diabetic neuropathy (nerve damage) 🔗

Neuropathy is among the most widespread complications, affecting an estimated 30% of all diabetes patients. The most common form, peripheral neuropathy, affects nerves in the feet, legs, and hands, causing numbness, tingling, burning pain, or complete loss of sensation. This loss of feeling is particularly dangerous for the feet: small cuts, blisters, or sores may go unnoticed, become infected, and in severe cases lead to gangrene and amputation. Autonomic neuropathy can affect the digestive system, urinary tract, heart rate regulation, and sexual function.

Cardiovascular disease 🔗

Diabetes roughly doubles the risk of cardiovascular disease. People with diabetes are more likely to develop coronary artery disease, suffer heart attacks and strokes, and experience peripheral artery disease. These macrovascular complications are responsible for the majority of diabetes-related deaths – approximately 75% of fatalities among people with diabetes are due to coronary artery disease. Controlling blood pressure, cholesterol, and blood sugar levels, along with avoiding smoking, are essential for reducing this risk.

Other complications 🔗

Beyond these major complications, uncontrolled diabetes also increases the risk of skin infections, hearing loss, cognitive decline and dementia, depression, gum disease, and bone disorders such as osteoporosis. MedlinePlus reports that diabetes can also weaken the immune system, making individuals more susceptible to serious infections.

The global burden and the path forward 🔗

The scale of the diabetes epidemic is staggering. The International Diabetes Federation estimates that 589 million adults aged 20-79 are currently living with diabetes, and this figure is projected to reach 853 million by 2050. Diabetes was responsible for 3.4 million deaths in 2024 alone and caused over one trillion USD in direct health expenditures. Alarmingly, about 43% of people with diabetes remain undiagnosed.

The WHO’s Global Diabetes Compact, launched in 2021, has set five global diabetes coverage targets for 2030, including ensuring 100% of people with Type 1 diabetes have access to affordable insulin and that 80% of diagnosed individuals achieve good glycemic control. Meanwhile, national programs like the CDC’s National Diabetes Prevention Program in the United States are working to make evidence-based lifestyle interventions more widely available.

The bottom line is that while Type 1 diabetes currently cannot be prevented, Type 2 diabetes is largely preventable – and when either form is diagnosed, effective management can prevent or significantly delay serious complications. A combination of healthy eating, regular physical activity, weight management, routine screening, and timely medical treatment forms the backbone of both prevention and care.

What do you think? Given that lifestyle changes alone can reduce Type 2 diabetes risk by over 50%, what barriers do you believe prevent people from adopting healthier habits – and how might communities and policymakers help remove those barriers?

References

1. https://www.who.int/initiatives/the-who-global-diabetes-compact/
2. https://www.who.int/news-room/fact-sheets/detail/diabetes
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC10958528/
4. https://www.paho.org/en/topics/diabetes
5. https://www.niddk.nih.gov/about-niddk/research-areas/diabetes/diabetes-prevention-program-dpp
6. https://www.ncbi.nlm.nih.gov/books/NBK549946/
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC10360374/
8. https://diabetesjournals.org/care/article/48/Supplement_1/S252/157552/12-Retinopathy-Neuropathy-and-Foot-Care-Standards
9. https://www.merckmanuals.com/professional/endocrine-and-metabolic-disorders/diabetes-mellitus-and-hypoglycemia/long-term-complications-of-diabetes-mellitus
10. https://www.heart.org/en/health-topics/diabetes/diabetes-complications-and-risks
11. https://medlineplus.gov/ency/patientinstructions/000327.htm
12. https://diabetesatlas.org/
13. https://www.cdc.gov/pcd/issues/2025/24_0273.htm