# Your Guide to Diet & Lifestyle for Prediabetes and Diabetes **Prepared by:** Pedro Cheung MD **Last Updated:** May 2026 **Based on 2025 American Diabetes Association Guidelines** --- > **Important Note:** This handout provides general guidance. Always work with your doctor, diabetes educator, or registered dietitian to create a plan that fits your specific needs, medications, and health goals. --- ## Understanding Your Diagnosis ### What Is Prediabetes? Prediabetes means your blood sugar (glucose) is higher than normal, but not yet high enough to be called type 2 diabetes. Think of it as an early warning signal. **The good news:** prediabetes can often be reversed — or progression to diabetes significantly delayed — with lifestyle changes alone. |Test|Normal|Prediabetes|Diabetes| |---|---|---|---| |Fasting Blood Sugar (mg/dL)|Less than 100|100–125|126 or higher| |A1C (%)|Below 5.7|5.7–6.4|6.5 or higher| |2-Hour Glucose Tolerance (mg/dL)|Below 140|140–199|200 or higher| ### What Is Type 2 Diabetes? Type 2 diabetes means your body either does not make enough insulin or cannot use it properly. Insulin is the "key" that lets sugar enter your cells for energy. When it doesn't work well, sugar builds up in the blood. Over time, high blood sugar can damage blood vessels, nerves, eyes, kidneys, and the heart. **The encouraging truth:** Even with a diabetes diagnosis, the right diet and lifestyle choices can dramatically improve your blood sugar, reduce your need for medication, and protect you from complications. --- ## Part 1: Eating for Better Blood Sugar The 2025 ADA Standards of Care recognize several eating patterns as effective for managing blood sugar. There is no single "diabetes diet" — the best plan is one you can stick with long-term. The core principles, however, are consistent across all healthy patterns. ### The Healthy Plate Method (Where to Start) Use a 9-inch dinner plate as your guide at every meal: ``` ┌────────────────────────────────────────┐ │ ½ PLATE │ │ NON-STARCHY VEGETABLES │ │ (broccoli, spinach, peppers, │ │ cucumber, zucchini, tomatoes) │ ├──────────────────┬─────────────────────┤ │ ¼ PLATE │ ¼ PLATE │ │ LEAN │ WHOLE GRAIN or │ │ PROTEIN │ STARCHY FOOD │ │ (chicken, fish, │ (brown rice, sweet │ │ eggs, beans, │ potato, lentils, │ │ tofu) │ whole wheat bread)│ └──────────────────┴─────────────────────┘ ``` Add a small serving of healthy fat (avocado, nuts, olive oil) and a glass of water. --- ### Foods to Eat More Often #### ✅ Non-Starchy Vegetables (Fill Half Your Plate) These have very little effect on blood sugar and are packed with fiber, vitamins, and minerals. Eat as much as you like! - Broccoli, cauliflower, Brussels sprouts - Spinach, kale, collard greens, arugula - Peppers (all colors), zucchini, summer squash - Cucumber, celery, asparagus, green beans - Tomatoes, mushrooms, onions, eggplant, cabbage - Salad greens of all kinds #### ✅ Quality Proteins (Fill a Quarter of Your Plate) Protein slows digestion and helps stabilize blood sugar. Choose lean or plant-based options most often. - **Fish and seafood:** Salmon, sardines, mackerel, tuna, cod, halibut (aim for at least 2 servings of oily fish per week — they contain heart-protective omega-3 fats) - **Poultry:** Chicken or turkey breast (skinless, baked/grilled, not fried) - **Eggs:** 1–2 eggs a few times per week (research shows the cholesterol in eggs does not significantly raise blood cholesterol for most people) - **Legumes:** Lentils, black beans, chickpeas, kidney beans, edamame — these are high in both protein AND fiber, making them excellent for blood sugar control - **Tofu and tempeh:** Excellent plant-based proteins - **Low-fat dairy:** Plain Greek yogurt, cottage cheese, low-fat milk or unsweetened soy milk - **Nuts and nut butters:** Almonds, walnuts, peanut butter (unsalted, no added sugar) #### ✅ Whole Grains and Complex Carbohydrates (Fill a Quarter of Your Plate) Unlike refined (white) grains, whole grains are digested slowly, causing a gentler rise in blood sugar. - Brown rice, wild rice, black rice - Whole wheat bread or pasta (look for "100% whole wheat" as the first ingredient) - Oatmeal (steel-cut or rolled oats — not instant or flavored packets) - Quinoa, barley, farro, bulgur - Sweet potatoes (with skin on for extra fiber) - Whole grain crackers **Portion tip:** A serving of cooked grains is about ½ to ¾ cup (the size of a tennis ball). #### ✅ Healthy Fats Fats do not raise blood sugar. Healthy fats actually help slow how quickly sugar enters your bloodstream and protect your heart. - Avocado (¼ to ½ per serving) - Extra-virgin olive oil (best for cooking at low-medium heat and for dressings) - Nuts: almonds, walnuts, pistachios, cashews (a small handful = 1 serving) - Seeds: chia seeds, flaxseeds, hemp seeds, pumpkin seeds - Fatty fish (salmon, sardines) — counts as both protein and healthy fat #### ✅ Fruits Yes, you can eat fruit! Fruit contains natural sugars but also fiber, vitamins, and antioxidants. Choose whole fruit over juice. Lower-sugar fruits include: - Berries (blueberries, strawberries, raspberries, blackberries) — best choices - Apples, pears, cherries, plums, peaches - Citrus fruits: oranges, grapefruit, clementines **Tip:** Eat fruit with a protein (like nuts or Greek yogurt) to slow the blood sugar rise. Limit portions to about 1 small piece or ½ cup at a time. --- ### Foods to Limit or Avoid #### ❌ Sugar-Sweetened Beverages — The Most Important One to Cut Liquid sugar raises blood sugar very fast and provides no nutritional benefit. The 2025 ADA guidelines specifically recommend drinking water instead of sugary or artificially sweetened drinks. - Regular sodas, lemonade, sweet tea, fruit punch - Fruit juices (even 100% juice — it's concentrated sugar without the fiber of whole fruit) - Energy drinks, sports drinks (unless treating low blood sugar) - Flavored coffee drinks, sweetened lattes **What to drink:** Plain water (aim for 8–10 cups/day), sparkling water, unsweetened coffee or tea, herbal teas. #### ❌ Refined Carbohydrates and White Starches These are digested quickly and spike blood sugar. - White bread, white rice, white pasta - Pastries, donuts, muffins, croissants - Sugary breakfast cereals - Crackers made with white flour - Most packaged snack foods (pretzels, chips, rice cakes) #### ❌ Added Sugars - Table sugar, honey, maple syrup, agave (small amounts may be used occasionally) - Candy, cookies, cakes, ice cream, pies - Chocolate bars, sweetened yogurt, flavored oatmeal packets - Jams, syrups, sweetened sauces and condiments #### ❌ Processed and Ultra-Processed Foods - Fast food (high in unhealthy fats, salt, and refined carbs) - Processed meats: bacon, sausage, hot dogs, deli meats (linked to increased diabetes risk) - Packaged meals, frozen dinners high in sodium - Fried foods of all kinds #### ❌ Saturated and Trans Fats (Limit These to Protect Your Heart) People with diabetes have higher risk of heart disease. Limiting saturated fat is now specifically recommended in 2025 ADA guidelines. - Butter, lard, coconut oil (use sparingly) - Full-fat red meat (beef, pork, lamb) — limit to 1–2 times/week, choose lean cuts - Full-fat dairy: cream, whole milk, full-fat cheese - Tropical oils: palm oil, coconut oil - **Avoid completely:** Trans fats found in partially hydrogenated oils (check ingredient labels) --- ### Evidence-Based Eating Patterns Research shows several eating patterns work well for blood sugar management. You do not need to follow one perfectly — use them as a guide. |Eating Pattern|What It Emphasizes|Evidence| |---|---|---| |**Mediterranean Diet**|Vegetables, fish, olive oil, legumes, whole grains, nuts; limited red meat|Reduces A1C by ~0.47%, promotes weight loss, best cardiovascular protection| |**Low-Carbohydrate**|Limiting carbs to 50–130g/day; emphasizing protein and healthy fat|Effective for short-term blood sugar reduction; may allow medication reduction| |**Plant-Based/Vegan**|Whole plant foods; eliminating or minimizing animal products|Improves insulin sensitivity, reduces A1C, supports weight loss| |**DASH Diet**|Low sodium, high fruit, vegetable, and whole grain intake|Lowers blood pressure alongside blood sugar| **Bottom line:** The Mediterranean diet has the strongest overall evidence for people with diabetes, combining blood sugar benefits with significant heart protection. However, the best diet is one you can maintain. Work with your dietitian to find your fit. --- ### Reading Food Labels: What to Look For When you pick up a packaged food, check these four things: 1. **Serving size** — All numbers are based on this. Many packages contain 2–3 servings. 2. **Total carbohydrates** — Aim for 30–45g of carbs per meal (your dietitian will help personalize this). 3. **Dietary fiber** — Aim for 5g or more per serving. Fiber slows blood sugar rise. 4. **Added sugars** — Should be as low as possible (ideally 0–5g). 5. **Saturated fat** — Aim for less than 3g per serving. **Ingredient list tip:** Avoid products where sugar (or any of its names: corn syrup, fructose, dextrose, cane juice) appears in the first three ingredients. --- ### Meal Planning Tips - **Eat at regular times** — Skipping meals can cause blood sugar to spike when you do eat. - **Don't skip breakfast** — A protein-rich breakfast stabilizes blood sugar all morning. - **Watch portions, not just food type** — Even healthy foods affect blood sugar in large amounts. - **Cook more at home** — Restaurant portions are large and often higher in fat, salt, and refined carbs. - **Meal prep on weekends** — Cook grains, roast vegetables, and portion proteins for the week ahead. - **Use cinnamon** — Small amounts added to food may modestly improve insulin sensitivity (add to oatmeal, coffee, or yogurt). - **Vinegar** — A tablespoon of apple cider vinegar before meals may help lower post-meal blood sugar for some people. Ask your doctor first if you take medications. #### Sample Day of Eating |Meal|What to Eat| |---|---| |**Breakfast**|¾ cup steel-cut oatmeal + 1 tbsp ground flaxseed + ½ cup blueberries + 2 boiled eggs or ¼ cup nuts| |**Mid-Morning Snack**|1 apple + 1 tbsp almond butter| |**Lunch**|Large salad with spinach, roasted vegetables, ½ cup chickpeas, grilled chicken, olive oil + lemon dressing + 2–3 whole grain crackers| |**Afternoon Snack**|Plain Greek yogurt + a small handful of walnuts| |**Dinner**|3 oz baked salmon + ¾ cup brown rice + 1 cup steamed broccoli + olive oil drizzle| |**Evening (if needed)**|½ cup cottage cheese or a small handful of almonds| --- ## Part 2: Physical Activity — Your Most Powerful Blood Sugar Tool Exercise works like a second dose of medicine. When your muscles work, they absorb glucose directly from your blood, even without insulin. Regular physical activity improves insulin sensitivity, supports weight loss, lowers blood pressure, reduces heart disease risk, and improves mood. **The 2025 ADA guidelines and international clinical guidelines recommend:** ### How Much Exercise? - **Aerobic exercise:** At least **150 minutes per week** of moderate-intensity activity (or 75 minutes of vigorous-intensity activity), spread over at least 3 days per week. Try not to go more than 2 days in a row without moving. - **Resistance training:** At least **2–3 sessions per week** on non-consecutive days. The 2025 ADA now specifically emphasizes combining resistance training with aerobic exercise for the best metabolic results. - **Reduce sitting time:** Break up long periods of sitting every 30 minutes by standing, walking, or doing light activity for 3–5 minutes. ### Types of Exercise #### Aerobic (Cardio) — Gets Your Heart Rate Up - Brisk walking (one of the best options — free, safe, effective) - Cycling (stationary or outdoor) - Swimming or water aerobics (ideal for those with joint pain) - Dancing - Jogging or running - Hiking **How to know if you're at the right intensity:** You should be able to talk in short sentences but not sing. If you can hold a full conversation without effort, work a little harder. If you can't say a word, slow down. #### Resistance / Strength Training — Builds Muscle, Burns Glucose Muscle tissue is one of the main places your body stores glucose. More muscle = better blood sugar control. - Free weights or dumbbells - Resistance bands (affordable, portable, great for beginners) - Weight machines at the gym - Bodyweight exercises: squats, push-ups, lunges, planks - Yoga or pilates (also improves flexibility and reduces stress) #### Flexibility and Balance - Stretching after every workout - Yoga or tai chi - These become especially important as we age to prevent falls and maintain mobility ### Getting Started Safely - **Before beginning:** Talk to your doctor, especially if you have heart disease, neuropathy (nerve damage), retinopathy (eye damage), or kidney problems. Some exercises may need to be modified. - **Start slowly:** Even 10-minute walks three times a day count. Build up gradually over weeks. - **Check your blood sugar:** If you take insulin or certain diabetes medications, check before and after exercise. Eat a small snack if blood sugar is below 100 mg/dL before exercising. - **Stay hydrated:** Drink water before, during, and after exercise. - **Wear proper footwear:** Especially important if you have neuropathy or foot problems. Check your feet before and after every workout. - **Carry fast-acting sugar:** If you are at risk for low blood sugar (hypoglycemia), keep glucose tablets, juice, or regular candy on hand during exercise. ### Signs of Hypoglycemia (Low Blood Sugar) During Exercise Stop exercising immediately and treat with 15–20g of fast-acting carbs if you experience: - Shakiness, sweating, dizziness - Rapid heartbeat, anxiety - Confusion or difficulty concentrating - Paleness, weakness **Treatment:** 4 glucose tablets, 4 oz (½ cup) of juice or regular soda, or 1 tablespoon of honey. Wait 15 minutes, recheck blood sugar. --- ## Part 3: Sleep — Now Recognized as Equal to Diet and Exercise The 2025 ADA guidelines made a landmark change: sleep health is now considered as important as diet and physical activity in diabetes management. This is a significant update. **Why sleep matters for blood sugar:** - Poor or insufficient sleep increases cortisol (a stress hormone that raises blood glucose). - Sleep deprivation causes insulin resistance — the same process that drives diabetes. - People who sleep less than 6 hours or more than 9 hours have higher rates of type 2 diabetes. - Sleep apnea (a common breathing disorder during sleep) is strongly linked to diabetes and worsens blood sugar control. ### ADA Sleep Recommendation: 7–9 Hours Per Night #### Tips to Improve Sleep Quality 1. **Keep a consistent schedule** — Go to bed and wake up at the same time every day, including weekends. 2. **Make your bedroom cool, dark, and quiet** — Use blackout curtains or an eye mask. 3. **Avoid screens 1 hour before bed** — Blue light from phones and tablets disrupts melatonin production. 4. **Limit caffeine after noon** — Caffeine can stay in your system for 6–8 hours. 5. **Avoid large meals and alcohol close to bedtime** — Both can disrupt sleep quality and blood sugar. 6. **Create a wind-down routine** — Read, take a warm bath, do gentle stretching, or practice deep breathing. 7. **Exercise during the day** — Regular activity improves sleep quality. Avoid intense exercise within 2–3 hours of bedtime. 8. **Manage blood sugar before bed** — High or low blood sugar at night disrupts sleep. Follow your doctor's advice on bedtime targets. #### Ask About Sleep Apnea If you snore loudly, wake up feeling unrefreshed, feel very sleepy during the day, or your partner notices you stop breathing during sleep — talk to your doctor. Sleep apnea is common in people with diabetes and significantly worsens blood sugar control. It is treatable with a CPAP machine or other therapies. --- ## Part 4: Stress Management Stress directly raises blood sugar. When you're stressed, your body releases hormones (cortisol, adrenaline) that tell the liver to release more glucose — a "fight or flight" response. Chronic stress can make diabetes very difficult to manage. ### Signs That Stress Is Affecting Your Blood Sugar - Blood sugar readings are consistently higher during stressful periods - You're overeating or undereating in response to stress - You're skipping workouts or medication - You're sleeping poorly - You feel anxious, irritable, or overwhelmed ### Effective Stress Reduction Strategies - **Deep breathing:** Slow, diaphragmatic breathing activates the parasympathetic nervous system and quickly lowers cortisol. Try 4 counts in, hold 4, out 6. - **Mindfulness meditation:** Even 10 minutes a day improves blood sugar and mental health over time. Apps like Calm, Headspace, or Insight Timer are helpful starting points. - **Yoga and tai chi:** Combine movement, breathing, and mindfulness. Studies show improvements in A1C, blood pressure, and stress markers. - **Nature walks:** Even short time spent outdoors reduces stress hormones. - **Journaling:** Writing about your feelings can help process emotions and identify stress patterns. - **Social connection:** Loneliness and isolation worsen diabetes outcomes. Stay connected with friends, family, or a support group. - **Therapy or counseling:** Cognitive behavioral therapy (CBT) is highly effective for anxiety and depression related to chronic illness. Ask your doctor for a referral. ### Diabetes Distress Is Real Living with diabetes — monitoring, medications, worry about complications — is emotionally demanding. "Diabetes distress" is not the same as clinical depression, but it is very common and can make self-management much harder. The 2025 ADA guidelines recommend screening for diabetes distress at key points in care. **Tell your care team if:** - You feel burned out or overwhelmed by diabetes management - You feel hopeless about your condition - You're struggling to follow your plan despite wanting to - Diabetes is affecting your relationships or quality of life You deserve support — both physical and emotional. --- ## Part 5: Weight Management For people with prediabetes or type 2 diabetes who are overweight, weight loss is one of the most effective interventions available. ### What the Evidence Shows - Losing just **5–7% of body weight** (about 10–14 pounds for a 200-pound person) can prevent or significantly delay the progression from prediabetes to type 2 diabetes. - Losing **10–15% of body weight** can meaningfully lower A1C, blood pressure, and cholesterol — sometimes allowing reduction in diabetes medication. - For some people with type 2 diabetes, significant weight loss (15%+) can achieve diabetes **remission** — blood sugars returning to normal without medication. ### Healthy Rate of Weight Loss Aim for 0.5–1 pound per week. Faster loss is hard to sustain and may cause muscle loss. Focus on building sustainable habits rather than rapid dieting. ### Practical Weight Management Strategies - **Don't skip meals** — Skipping meals often leads to overeating later and blood sugar swings. - **Choose volume over restriction** — Fill up on high-fiber, low-calorie foods (vegetables, broth-based soups) before eating higher-calorie foods. - **Reduce portion sizes gradually** — Use smaller plates, measure portions until you develop an eye for serving sizes. - **Limit eating out** — Restaurant portions are typically 2–3x the recommended serving size. - **Eat slowly** — It takes 20 minutes for your brain to register fullness. Put your fork down between bites. - **Food journal** — Even 2 weeks of tracking what you eat can reveal patterns and portions you didn't realize. - **Ask about the Diabetes Prevention Program (DPP)** — This CDC-recognized program provides structured lifestyle coaching and has been shown to reduce diabetes risk by 58% in research trials. It's often free or low-cost through insurance. Ask your doctor for a referral. --- ## Part 6: Alcohol, Smoking, and Other Lifestyle Factors ### Alcohol - If you choose to drink, do so in moderation: **up to 1 drink/day for women, up to 2 drinks/day for men** (1 drink = 12 oz beer, 5 oz wine, or 1.5 oz spirits). - **Never drink on an empty stomach** — alcohol can cause dangerous drops in blood sugar, especially if you take insulin or sulfonylurea medications. - Alcohol can cause delayed hypoglycemia (up to 12–24 hours later). Check blood sugar before bed if you've been drinking. - Avoid sweet wines, flavored liquors, and mixers made with juice or soda. ### Smoking - Smoking significantly worsens insulin resistance and dramatically increases the risk of every diabetes complication: heart attack, stroke, kidney disease, neuropathy, vision loss. - **Quitting smoking is one of the most important things you can do for your health.** Ask your doctor about nicotine replacement therapy, medications (such as varenicline/Chantix or bupropion), and cessation programs. ### Cannabis The 2025 ADA guidelines newly address cannabis: it may affect blood sugar unpredictably, impair judgment about self-care, and lead to overeating. If you use cannabis, discuss this openly with your doctor. --- ## Part 7: Monitoring Your Progress Regular check-ins with your health care team help you see what's working and adjust your plan. ### Key Numbers to Know |Measurement|Target (Ask Your Doctor for Your Goal)|Frequency to Check| |---|---|---| |**A1C**|Below 7% for most adults; individualized|Every 3–6 months| |**Fasting Blood Sugar**|80–130 mg/dL (before meals)|As directed by your doctor| |**Blood Pressure**|Below 130/80 mmHg|At every visit| |**LDL Cholesterol**|Below 100 mg/dL (below 70 if heart disease present)|Annually| |**Weight/BMI**|Work toward a healthy weight|Monthly| |**Foot exam**|No sores, redness, or numbness|Self-check weekly; doctor check annually| |**Eye exam**|No retinopathy detected|Annually (with dilation)| |**Kidney function (urine albumin, eGFR)**|Within normal range|Annually| ### Home Blood Sugar Monitoring If your doctor recommends checking blood sugar at home: - Keep a log or use an app to track patterns. - Check at the times your doctor recommends (before meals, 2 hours after meals, before bed, or before/after exercise). - Target ranges: **80–130 mg/dL before meals** and **less than 180 mg/dL two hours after meals** (for most adults). - Continuous Glucose Monitors (CGM) — small sensors worn on the arm or abdomen — are increasingly recommended. They track blood sugar every few minutes and can show you exactly how food, exercise, and stress affect your blood sugar in real time. Ask your doctor if a CGM is right for you. --- ## Quick Reference: Daily Habits for Better Blood Sugar ### Every Day, Aim For: - [ ] Fill half your plate with non-starchy vegetables at every meal - [ ] Drink 8–10 cups of water (avoid sugary drinks) - [ ] Eat protein at every meal to slow blood sugar rise - [ ] Choose whole grains over refined grains - [ ] Move your body — even a 10-minute walk after meals helps - [ ] Break up long sitting time every 30 minutes - [ ] Take medications as prescribed - [ ] Check blood sugar as directed - [ ] Get 7–9 hours of sleep - [ ] Practice one stress-reduction activity (breathing, stretching, meditation) ### Weekly Goals: - [ ] 150+ minutes of moderate aerobic activity - [ ] 2–3 sessions of resistance/strength training - [ ] Eat fish at least twice (especially fatty fish like salmon or sardines) - [ ] Eat legumes (beans, lentils) at least 3 times - [ ] Check your feet for any changes - [ ] Review your blood sugar log or CGM trends --- ## When to Call Your Doctor **Call right away if you experience:** - Blood sugar consistently above 250 mg/dL - Symptoms of hypoglycemia that do not improve with treatment - Severe thirst, frequent urination, blurred vision, or unexplained weight loss - Chest pain, shortness of breath, or swelling in your legs - A foot wound, sore, or infection that isn't healing - Nausea, vomiting, and inability to keep fluids down --- ## Resources and Support - **American Diabetes Association:** diabetes.org | 1-800-DIABETES (1-800-342-2383) - **National Institute of Diabetes and Digestive and Kidney Diseases:** niddk.nih.gov - **Diabetes Prevention Program (DPP) Locator:** cdc.gov/diabetes/prevention - **Registered Dietitian Finder:** eatright.org - **Certified Diabetes Care and Education Specialist (CDCES) Finder:** cbdce.org --- ## Key Points to Remember 1. **Prediabetes is reversible.** Type 2 diabetes is manageable. You have real power to change your trajectory. 2. **Small changes add up.** You don't need to be perfect — every healthy meal, every walk, every good night of sleep moves you in the right direction. 3. **No single food causes diabetes, and no food is completely forbidden.** It's about overall patterns and portions. 4. **Sleep and stress management are just as important as diet and exercise** — this is now official guidance from the ADA. 5. **You are not alone.** Millions of people successfully manage diabetes and prediabetes. Ask for support from your care team, family, and community. --- _This handout is based on the 2025 American Diabetes Association Standards of Care in Diabetes, NIDDK guidelines, and current evidence-based nutrition and lifestyle research. It is intended for educational purposes and does not replace individualized medical advice. Please work with your health care provider to personalize these recommendations for your situation._ _Last updated: May 2026_