Adopting a vegan diet can provide many health benefits, including weight loss, lower cholesterol, and reduced risk of chronic diseases like heart disease and diabetes. However, some people find that their blood sugar rises after switching to a vegan diet. There are a few potential reasons why this may occur.
Too Many Processed Foods
While a well-planned vegan diet focused on whole foods is very healthy, not all vegan diets are created equal. Some vegan diets may rely too heavily on processed vegan foods like:
- Vegan frozen meals
- Vegan meat alternatives
- Vegan desserts and snacks
- Vegan protein bars
These types of foods are often high in added sugars, refined carbs, and unhealthy fats. Eating too many processed foods, even if they are vegan, can cause spikes in blood sugar.
Try Focusing on Whole Foods
To improve blood sugar control, focus your diet around whole, unprocessed plant foods like:
- Vegetables
- Fruits
- Beans and legumes
- Whole grains
- Nuts and seeds
Limit processed vegan foods and choose whole food options whenever possible.
Too Many Quickly Digested Carbs
Some types of carbohydrates get digested and absorbed very quickly, leading to spikes in blood sugar. These include:
- Sugars – such as table sugar, agave nectar, maple syrup
- Refined grains – like white bread, white rice, and white pasta
- Starchy vegetables – such as white potatoes and corn
Focusing too much on these foods may result in frequent blood sugar spikes. Try to limit high-glycemic foods and replace them with healthier, low-glycemic options:
| High Glycemic | Low Glycemic |
|---|---|
| White bread | 100% whole grain bread |
| White rice | Brown rice |
| White potato | Sweet potato |
| Soda | Sparkling water with lemon |
Limit Portion Sizes of Starchy Carbs
When eating starchy carbs like whole grains and starchy vegetables, pay attention to your portion sizes. Keep portions to:
- 1/2 cup cooked grains
- 1 medium baked sweet or regular potato
- 3/4 cup cooked beans or lentils
Spreading carb intake over the day can also help prevent blood sugar spikes.
Not Enough Fiber
Fiber slows digestion and the absorption of sugar into the bloodstream. Vegan diets can be low in fiber if they don’t contain enough whole plant foods.
To get more fiber, make sure to eat plenty of:
- Beans and lentils
- Nuts and seeds
- Whole grains
- Vegetables
- Fruit
Aim for at least 25-35 grams of fiber per day. Spread fiber intake throughout the day by including a source of fiber at each meal.
Include High-Fiber Foods at Each Meal
Make an effort to include a high-fiber food at each meal. For example:
- Breakfast: Oatmeal with fruit and nuts
- Lunch: Veggie sandwich on whole grain bread with avocado
- Dinner: Lentil soup with whole grain crackers
Too Much Fruit
Fruit is very healthy, but it’s also fairly high in natural sugars. While whole fruit is very different from added sugars, eating large amounts can still lead to blood sugar spikes.
It’s usually best to stick to 1-2 servings of fruit per day, focusing on fruits lower in sugar like berries and apples. Larger servings of tropical fruits or dried fruits should be avoided if you’re trying to reduce blood sugar levels.
Stick to Small-Medium Sized Portions of Fruit
These portion sizes contain 15-30 grams of carbs:
- 1 small apple, orange, pear, etc.
- 1 cup berries or melon cubes
- 1/2 medium banana
- 2 small figs or plums
Spread fruit intake throughout the day rather than eating large amounts at once.
Too Little Fat and Protein
Eating adequate amounts of protein and healthy fats can help stabilize blood sugar levels. Some vegan diets are very low in fat or protein.
Include good sources of plant-based protein and fats at meals like:
- Tofu, tempeh, edamame
- Nuts and nut butters
- Seeds
- Avocado
- Coconut
- Olives and olive oil
These help balance out the blood sugar impact of carbohydrates.
Include Plant Protein and Healthy Fats at Each Meal
When building meals and snacks, include plant proteins and fats in addition to fruits, vegetables and whole grains. For example:
- Breakfast: Tofu scramble with veggies and avocado
- Lunch: Lentil and chickpea salad with olive oil dressing
- Snack: Edamame and walnuts
Excess Alcohol Intake
While moderate alcohol intake may be healthy, excess intake can cause blood sugar problems. Alcohol inhibits the liver’s ability to produce glucose, leading to low blood sugar (hypoglycemia). To compensate, the body releases excess glucose and insulin.
Plus, the calories from alcohol are often added on top of usual calorie intake, resulting in weight gain over time. Excess weight contributes to insulin resistance and high blood sugar.
If you choose to drink alcohol, stick to moderate intake of no more than:
- 1 drink per day for women
- 2 drinks per day for men
Make sure to account for alcohol within your daily calorie needs to avoid weight gain.
Limit Alcohol Intake and Avoid Excess Calories
- Stick to 1-2 standard servings max per day
- Beware of “hidden” calories from mixers and sugary cocktails
- Drink plenty of water between alcoholic drinks
- Eat a healthy meal before or while drinking to avoid low blood sugar
Too Much Stress
High amounts of stress raise cortisol and other hormones that lead to blood sugar spikes. Additionally, chronic stress can cause overeating behaviors that result in weight gain.
Managing stress through relaxation techniques, adequate sleep, social connection, and counseling may help normalize blood sugar. Exercise is also great for busting stress.
Reduce Stress Levels to Improve Blood Sugar Control
- Try stress-reducing activities like yoga, meditation, walking
- Make time for hobbies and social activities
- Aim for 7-9 hours of sleep per night
- Seek counseling or support if needed
Sedentary Lifestyle
Regular exercise helps stabilize blood sugar in several ways. It burns calories to aid weight loss, builds muscle mass that uptake glucose, and makes cells more sensitive to insulin.
Aim for 150-300 minutes per week of moderate exercise like brisk walking or gentle cycling. Any movement throughout the day helps – take breaks to walk around, use a standing desk, take the stairs, etc.
Increase Physical Activity Levels
- Take a 30-60 minute walk 4-5 days per week
- Try yoga, swimming, cycling, aerobics classes
- Use a fitness tracker to monitor daily movement
- Take movement breaks every 30-60 minutes when working
Medical Conditions or Medications
Certain medical conditions also increase the risk of high blood sugar, including:
- Polycystic ovary syndrome (PCOS)
- Cushing’s disease
- Hyperthyroidism
- Chronic pancreatitis
Additionally, some medications can raise blood sugar such as corticosteroids, antipsychotics, and hormone therapy drugs.
It’s important to work with your doctor to control any underlying condition. Never stop medication unless advised by your physician. Lifestyle changes can help reduce blood sugar levels, but medical treatment may also be needed.
See Your Doctor to Evaluate Any Contributing Conditions
- Get necessary lab testing for diagnosis
- Discuss optimal treatment options
- Ask about alternative medication if needed
- Monitor blood sugar closely when starting new medications
Pre-Diabetes or Diabetes
In some cases, persistently high blood sugar may be caused by pre-diabetes or diabetes. Pre-diabetes refers to blood sugar levels that are higher than normal but not high enough for a diagnosis of diabetes.
Without lifestyle changes, pre-diabetes often leads to type 2 diabetes over time. Diabetes requires medical treatment to prevent complications.
Risk factors for pre-diabetes and type 2 diabetes include:
- Overweight or obesity
- Family history
- Older age (45+ years)
- Gestational diabetes
- Sedentary lifestyle
- Unhealthy diet
See your doctor if you have persistent blood sugar spikes for diagnosis and treatment options.
Get Tested for Pre-Diabetes or Diabetes
- Fasting blood glucose test – normal is less than 100 mg/dL
- Hemoglobin A1C test – normal is less than 5.7%
- Oral glucose tolerance test
Making healthy lifestyle choices can help reverse pre-diabetes and prevent progression to diabetes.
Conclusion
There are many potential reasons why blood sugar levels may increase on a vegan diet, but the most common causes include too many processed foods, quickly digested carbs, inadequate fiber, excess fruit intake, insufficient protein and fat, high alcohol intake, excessive stress, sedentary lifestyle, certain medications or medical conditions like pre-diabetes.
Carefully following a well-balanced vegan diet focused on whole foods, getting regular exercise, managing stress, and visiting your doctor for regular check-ups can help maintain normal blood sugar levels.
Monitor your post-meal blood sugar with a home tester to identify problem areas in your diet. Keeping detailed food and symptom records can also help pinpoint triggers of elevated blood sugar.
With some simple diet and lifestyle adjustments, you can enjoy the many benefits of vegan eating while keeping your blood sugar in a healthy range.