Diabetes Explained: A Simple Guide for Everyone
By Dr S. Nishanth
MD, DNB (General Medicine), MRCP (UK), FNB (Critical Care), EDIC, FECMO
Internist, Intensivist & ECMO Consultant
Head, Department of Critical Care Medicine, SKS Hospital and Postgraduate Medical Institute, Salem
Published: 31 October 2026
The Short Answer
Diabetes means the sugar (glucose) level in your blood stays too high. This happens because the body either does not make enough insulin or cannot use it properly [1]. Over the years, high sugar damages the nerves and blood vessels. This can harm the eyes, kidneys, heart and feet [1].
The good news: type 2 diabetes, the most common kind, can be controlled well. The foundation is food, movement, weight control and regular check-ups. Medicines are added when needed [1,3].
Five things to remember:
- Diabetes is a lifelong condition that needs steady care, not a one-time fix.
- Your HbA1c (a 3-month sugar report) is the best measure of control.
- Eat from a balanced plate. You do not need to give up all your favourite foods.
- Move daily, even in small amounts.
- Never stop or change medicines on your own.
Know your numbers. Eat smart. Move daily. Visit your doctor regularly.
Diabetes in Detail: Your Questions Answered
What exactly is diabetes?
When you eat, your food turns into glucose. A hormone called insulin, made by the pancreas, lets glucose enter your body’s cells for energy. In diabetes, there is too little insulin or the body does not respond to it well, so glucose builds up in the blood [1].
There are three main types [1]:
- Type 1: the body makes almost no insulin. Daily insulin is required.
- Type 2: the body does not use insulin well. This is more than 95% of all cases, and it is often preventable.
- Gestational diabetes: it appears during pregnancy and raises the future risk of type 2.
What are the symptoms?
Common signs are intense thirst, passing urine often, blurred vision, tiredness and unplanned weight loss [1]. In type 2 diabetes, symptoms can be mild, and many people have no symptoms for years [1]. This is why a blood test is the only reliable way to know.
What is HbA1c?
HbA1c (also called A1C) is a blood test that shows your average blood sugar over the past two to three months [2]. It does not need fasting.
| Result | HbA1c |
|---|---|
| Normal | Below 5.7% |
| Prediabetes | 5.7% to 6.4% |
| Diabetes | 6.5% or higher |
Source: [2]
You can think of it as a 3-month report card, while a finger-prick reading is a snapshot of one moment.
Most adults with diabetes aim for an HbA1c below 7%, though your doctor may set a different target based on your age and other health conditions. It is usually checked at least twice a year, and whenever treatment changes [3].
Your doctor may also use other tests to diagnose diabetes: fasting sugar of 126 mg/dL or higher, or a 2-hour sugar of 200 mg/dL or higher [2].
Do I definitely have to take tablets for sugar?
Not always, and not forever in every case. It depends on your sugar levels, your HbA1c and your overall health.
- Lifestyle changes are the foundation of every diabetes plan [1,3].
- Some people with early or mild diabetes can control it with food, exercise and weight loss alone.
- Many others need medicines. The most common first medicine is metformin, which reduces the sugar made by the liver and helps the body respond to insulin [3].
- Other medicines are added if needed. Insulin is used when diet, exercise and tablets no longer keep sugar in range, and it is now often started earlier than in the past. This does not mean you have “failed” [3].
- Many people also need medicines for blood pressure and cholesterol to protect the heart and kidneys [1,3].
Worth knowing: WHO reports that 59% of adults aged 30 and over with diabetes were not taking any medicine for it [1]. Untreated diabetes leads to complications. If your doctor advises medicines, taking them regularly protects you.
Never stop tablets or insulin because your sugar “looks normal”. Normal readings often mean the medicine is working.
What should I eat?
There is no single “diabetes diet” [3]. A simple method is the Diabetes Plate, using a medium-sized plate [4]:
- Half the plate: non-starchy vegetables, such as greens, beans (French beans), cabbage, cauliflower, brinjal, bhendi, capsicum and tomato.
- One quarter: protein, such as dal, sprouts, fish, egg, chicken, paneer or tofu.
- One quarter: carbohydrates, such as rice, chapati, ragi or other whole grains. Choose whole grains over refined ones [3,4].
Other helpful habits:
- Eat regular meals in smaller portions [3]. Do not skip meals, especially if you take tablets or insulin.
- Choose fibre-rich foods such as whole grains, dals, vegetables and whole fruit [3,6].
- Eat whole fruit instead of fruit juice [4], and keep portions sensible. One serving at a time is a good rule.
- Drink water. Unsweetened tea or coffee is also fine [4].
What should I avoid or limit?
- Sugary drinks: soft drinks, packaged juices, sweet tea and sports drinks [6]. These raise sugar fastest.
- Sweets, sugar and refined foods: limit refined grains, sweets and starchy foods in large amounts [3].
- Too much white rice, maida and bakery items.
- Fried and packaged foods: the ICMR-NIN dietary guidelines for Indians advise limiting high-fat foods, sugar, salt and ultra-processed foods [7].
- Salt: keep sodium under 2,300 mg a day [6]. That is roughly one level teaspoon of salt in total, and much of it hides in pickles, papads and packaged foods.
Can I eat non-vegetarian food? Are there restrictions?
Yes. Lean protein from animals or plants is part of a healthy diabetes plate [4,6].
- Good choices: fish, skinless chicken, egg and seafood. Fatty fish such as salmon, sardines and mackerel give healthy omega-3 fats [6].
- Cooking matters more than the meat. Grilled, steamed, baked or lightly sautéed is better than deep-fried. Avoid heavy gravies made with a lot of oil, cream or coconut.
- Limit red meat (mutton, beef, pork) and processed meat (sausages, bacon). This is my practical advice for people with diabetes and heart risk.
- Eggs: for most people, one a day is fine. If your cholesterol is high, ask your doctor.
- Portion: keep meat to about a quarter of the plate, and do not skip vegetables.
- Avoid biryani and fried rice in large portions. The rice, not just the meat, raises sugar.
What type of oil should I use, and how much?
- Choose unsaturated fats such as olive oil, and other healthy oils, nuts and fish [3,6]. Rotating between oils such as groundnut, sesame, mustard or rice bran is reasonable, as no single oil is perfect.
- Avoid vanaspati, dalda and ghee in large amounts, and avoid reusing the same oil for repeated frying. These are my practical recommendations.
- Keep portions small [6]. As a practical guide, many dietitians suggest about 3 to 4 teaspoons of cooking oil per person per day, including all cooking. This is my practical advice, not a figure from the sources below. Your own need depends on your weight and health, so confirm it with your dietitian.
- Easy ways to cut oil: steam, boil, grill, pressure cook or use a non-stick pan. Measure oil with a spoon instead of pouring, and buy oil in small bottles for the month.
How do I lose weight?
Weight loss is one of the most powerful treatments for type 2 diabetes. Losing even about 5% of your body weightimproves blood sugar, cholesterol, triglycerides and blood pressure, and more loss brings more benefit [3]. For a person weighing 80 kg, 5% is about 4 kg.
A realistic approach:
- Cut sugary drinks and sweets first. This is the easiest big win.
- Reduce portions of rice and chapati, and fill up on vegetables and dal.
- Avoid fried snacks and packaged foods.
- Eat slowly and at regular times. Avoid late-night heavy dinners.
- Move more every day (see the next section).
- Aim for slow, steady loss of about 0.5 kg per week.
- Ask your doctor about further options if lifestyle changes are not enough. Weight-loss medicines or surgery may suit some people with a high BMI [3].
Avoid crash diets and “sugar-cure” products. They are unsafe, especially if you take diabetes medicines.
How much exercise do I need?
Aim for about 150 minutes of moderate activity a week, such as brisk walking [1,5]. That is about 30 minutes, five days a week. Spread it over at least 3 days a week, and do not go more than 2 days in a row without activity [5].
Add strength exercises (for example, light weights, resistance bands or body-weight exercises) at least twice a week[3,5]. Also break up long sitting every 30 minutes by standing or walking for a few minutes [3,5].
I can’t walk because of knee pain. What can I do?
Knee pain is a common problem, and it should not stop you from staying active. Experts advise starting with very small amounts, such as 5 minutes a day, and building up slowly. Water-based exercise, such as swimming or water walking, is a good option when weight-bearing or arthritis limits activity [5].
Other options I commonly suggest (your doctor or physiotherapist can tailor them to you):
- Chair exercises: seated leg raises, arm circles and seated marching.
- Stationary cycling with low resistance, which puts less load on the knees.
- Upper-body exercises with light weights or bands.
- Short walks on flat ground, several times a day, instead of one long walk.
- See a doctor or physiotherapist for the knee itself. Treating the pain, and losing weight, often helps the knee as well.
- Wear proper footwear.
Even if you can only do a little, doing something every day is better than doing nothing.
How do I take care of my feet, eyes and kidneys?
High sugar can damage these slowly, without pain at first, so regular checks are essential.
- Feet: wash and dry daily, including between the toes. Check for cuts, blisters, colour change or swelling. Do not walk barefoot. See your doctor about any sore that is not healing [3].
- Eyes: have a routine eye exam, ideally once a year or as your doctor advises [3].
- Kidneys, heart and blood pressure: WHO recommends kidney screening, foot care and eye exams, and many people need blood pressure medicines and statins to lower the risk of complications [1]. Ask your doctor which tests apply to you.
- Do not smoke. Tobacco worsens the risk of complications [1].
What is low blood sugar, and what should I do?
Some diabetes medicines, especially insulin and sulfonylurea tablets, can make the sugar fall too low [3]. Warning signs include sweating, shakiness, hunger, headache, confusion or sudden weakness.
- If you are awake and able to swallow, take quick sugar, such as glucose, sugar in water, or fruit juice, then recheck your sugar after 15 minutes.
- If the person is drowsy, confused or unconscious, go to a hospital at once.
- Always carry some sugar with you, and never skip meals after taking these medicines.
How often should I check my sugar?
Your doctor will advise this. It might be once a day, around exercise, or more often if you take insulin. Options include a home glucose meter, with readings written in a log, or a continuous glucose monitor [3].
Lifestyle Plan at a Glance
| Area | What to do |
|---|---|
| Food | Half plate vegetables, quarter protein, quarter whole grains |
| Drinks | Water, unsweetened tea or coffee. Avoid sugary drinks |
| Oil | Small amounts, healthy oils, less frying |
| Salt | Low. Watch pickles and packaged foods |
| Exercise | About 150 minutes a week, plus strength training twice a week |
| Weight | Aim to lose about 5% of body weight if overweight |
| Medicines | Take as prescribed. Never stop on your own |
| Check-ups | HbA1c at least twice a year, plus eye, foot, kidney checks |
| Habits | No tobacco, regular sleep, manage stress |
Key Takeaways
- Diabetes means high blood sugar from too little or poorly working insulin.
- HbA1c is your 3-month sugar report. For most adults, below 7% is the aim.
- Lifestyle comes first, and many people also need medicines. Never stop them on your own.
- Use the plate method, cut sugary drinks, and choose whole grains and fibre.
- Non-vegetarian food is allowed. Choose lean, lightly cooked options.
- Use small amounts of healthy oil.
- Keep moving. If your knees hurt, try chair, water or cycling exercises.
- Even a 5% weight loss makes a real difference.
- Check your feet, eyes and kidneys regularly, because complications are silent at first.
About the Author
Dr S. Nishanth (MD, DNB General Medicine, MRCP UK, FNB Critical Care, EDIC, FECMO) is an Internist, Intensivist and ECMO consultant with over 15 years of clinical experience. He is Head of the Department of Critical Care Medicine at SKS Hospital and Postgraduate Medical Institute, Salem, and offers care from outpatient consultations to ICU management, including diabetes and its complications, fever and sepsis, hypertension, pneumonia and ARDS.
Contact: SKS Hospital and Postgraduate Medical Institute, Salem – 636004 | +91 88070 86743 | nishanth.aarnish@gmail.com
Website: drsnishanth.com Instagram: @dr_s.nishanth
References
- World Health Organization (WHO). Diabetes (fact sheet). https://www.who.int/news-room/fact-sheets/detail/diabetes (accessed 31 October 2026)
- American Diabetes Association. Diabetes Diagnosis & Tests. https://diabetes.org/about-diabetes/diagnosis (accessed 31 October 2026)
- Mayo Clinic. Type 2 diabetes: Diagnosis and treatment. https://www.mayoclinic.org/diseases-conditions/type-2-diabetes/diagnosis-treatment/drc-20351199 (accessed 31 October 2026)
- American Diabetes Association. Plan Your Diabetes Plate (1-2-3). https://professional.diabetes.org/sites/dpro/files/2025-05/PE25-Plan-Your-Plate-FINAL-5-22-25.pdf (accessed 31 October 2026)
- Sigal RJ, et al. How to prescribe exercise in type 2 diabetes. American Diabetes Association. https://professional.diabetes.org/sites/default/files/media/sigal_how_to_prescribe_exercise_final.pdf (accessed 31 October 2026)
- American Diabetes Association. Nutrition FAQs. https://professional.diabetes.org/sites/dpro/files/2023-12/nutritionfaqs.pdf (accessed 31 October 2026)
- ICMR-NIN. Dietary Guidelines for Indians, 2024. Summary used: All India Radio. https://newsonair.gov.in/icmr-releases-updated-dietary-guidelines-for-indians-in-2024 (accessed 31 October 2026)
Disclaimer: This article is for public awareness and does not replace advice from your treating doctor. Diabetes treatment must be individualised. Do not start, stop or change medicines or diet without consulting your doctor.
