A low glycemic diet plan is a strategic approach to eating that prioritizes foods with a minimal impact on blood glucose levels. This article provides a detailed review of low glycemic diet plans, including what they are, how to follow them, and their benefits and drawbacks.
Understanding the Basics of Low Glycemic Diet Plans
At its core, a low glycemic diet is based on the glycemic index (GI), a measurement system that ranks foods according to their effect on your blood sugar levels. The GI was created in the early 1980s by Dr. David Jenkins, a Canadian professor. The rates at which different foods raise blood sugar levels are ranked in comparison with the absorption of 50 grams of pure glucose. Pure glucose is used as a reference food and has a GI value of 100.
What is the Glycemic Index?
The glycemic index (GI) assigns a number to a food based on how quickly it can raise your blood glucose levels. These carbohydrate-containing foods are ranked on a scale of 0 to 100 and divided into low, medium, and high-glycemic categories:
- Low: 55 or less
- Medium: 56 to 69
- High: 70 or more
Foods with a low GI value are the preferred choice because they’re slowly digested and absorbed, causing a slower and smaller rise in blood sugar levels. On the other hand, foods with a high GI value should be limited because they’re quickly digested and absorbed, resulting in a rapid rise and fall of blood sugar levels.
Glycemic Load (GL)
The rate at which foods raise blood sugar levels depends on three factors: the types of carbs they contain, their nutrient composition, and the amount you eat. To solve this, the glycemic load (GL) rating was developed. The GL is a measure of how a carb affects blood sugar levels, taking both the type (GI) and quantity (grams per serving) into account.
Read also: Navigating the Low Glycemic Diet
The GL ratings are:
- Low: 10 or less
- Medium: 11 to 19
- High: 20 or more
The GI is still the most important factor to consider when following the low GI diet. Otherwise, the easiest way to aim for a GL under 100 is to choose low GI foods when possible and consume them in moderation.
Factors Influencing GI Value
A number of factors can influence the GI value of a food or meal, including:
- The type of sugar it contains: The GI of sugar ranges from as low as 23 for fructose to up to 105 for maltose. Therefore, the GI of a food partly depends on the type of sugar it contains.
- The structure of the starch: Starch is a carb comprising two molecules: amylose and amylopectin. Amylose is difficult to digest, while amylopectin is easily digested. Foods with a higher amylose content will have a lower GI.
- How refined the carb is: Processing methods like grinding and rolling disrupt amylose and amylopectin molecules, raising the GI. Generally speaking, the more processed a food is, the higher its GI.
- Nutrient composition: Adding protein or fat to a meal can slow digestion and help reduce the glycemic response to a meal.
- Cooking method: Preparation and cooking techniques can affect the GI too. Generally, the longer a food is cooked, the faster its sugars will be digested and absorbed, raising the GI.
- Ripeness: Unripe fruit contains complex carbs that break down into sugars as the fruit ripens. The riper the fruit, the higher its GI. For example, an unripe banana has a GI of 30, while an overripe banana has a GI of 48.
- Acidic foods: Acidic foods seem to help lower the GI of certain foods.
Benefits of Following a Low Glycemic Diet Plan
Studies have shown that the low GI diet may result in weight loss, reduce blood sugar levels, and lower the risk of heart disease and type 2 diabetes. Here are some specific benefits:
Blood Sugar Control
Research suggests that low GI diets reduce blood sugar levels in people with diabetes. A 2019 review of 54 studies concluded that low GI diets reduced hemoglobin A1C (a long-term marker of blood sugar control), body weight, and fasting blood sugar levels in people with prediabetes or diabetes. The low glycemic diet is designed to control blood sugar levels by prioritizing foods that have a minimal impact on blood glucose.
Read also: Acne and the Low GI Diet
- Type 2 Diabetes Control: For individuals with type 2 diabetes, the low glycemic diet offers a practical and sustainable approach to managing blood sugar. By choosing foods with a lower glycemic index, you can minimize blood sugar spikes, reduce insulin resistance, and enhance overall glucose control. This can lead to improved energy levels, weight management, and a reduced need for medication.
- Pre-diabetes Management: If you've been diagnosed with pre-diabetes, adopting a low glycemic diet can help prevent or delay the onset of type 2 diabetes. It focuses on slow-digesting carbohydrates, such as whole grains, legumes, and non-starchy vegetables, which promote stable blood sugar levels and reduce the risk of progression.
- Insulin Resistance Reversal: Insulin resistance occurs when the body's cells become less responsive to the hormone insulin, leading to elevated blood sugar levels. The low glycemic diet can help reverse insulin resistance by reducing the demand for insulin secretion.
Weight Management
Following a low-GI diet helps you manage your appetite and as a result may help manage weight. One reason for this is that these sorts of foods tend to keep you feeling fuller for longer. Eating more fiber and reducing sugar intake will help keep your blood sugar levels under control.
Improved Cholesterol Levels
A 2019 study showed that low GI diets reduce total cholesterol and LDL (bad) cholesterol. LDL is associated with an increased risk of heart disease and stroke. Low-GI diets have been shown to significantly decrease total cholesterol and LDL (low-density lipoprotein) cholesterol levels.
Reduced Risk of Chronic Diseases
Moreover, the low GI diet has been shown to reduce the risk of macrosomia. This is a condition in which newborns have a birth weight over 8 pounds and 13 ounces, and it’s associated with numerous short- and long-term complications for the mother and baby. Research has strongly associated high GI and GL diets with an increased risk of heart disease. Some research suggests that people who consume high GI diets are more likely to develop certain types of cancer, including endometrial, colorectal, and breast cancer, compared with people on low GI diets. Low-GI diets have been associated with improved prevention of coronary heart disease in both diabetic and healthy subjects.
PCOS Support
Polycystic ovary syndrome (PCOS) is often associated with insulin resistance. By following a low glycemic diet, you can help regulate insulin levels and promote hormonal balance. This can aid in weight management, regulate menstrual cycles, reduce the risk of diabetes, and improve fertility outcomes for women with PCOS.
Gestational Diabetes Management
In gestational diabetes mellitus (GDM), a low-GI diet has been associated with less need for insulin and lower birth weights for babies.
Read also: Keto Bread for Diabetics
How to Follow a Low Glycemic Diet Plan
General Guidelines
There’s no need to count calories or track your protein, fat, or carbs on the low GI diet. Instead, the low GI diet involves swapping high GI foods for low GI alternatives. It’s easy to eat more food than you need without realizing it. Keeping track of and limiting how many carbs you eat at each meal can help manage your blood sugar levels.
- Prioritize Low Glycemic Foods: Select predominantly low-GI foods - these are typically brown (wholegrain) versions of carb foods like pasta, rice and crackers. Generally, the less processed a food, the more likely it is to have a low-GI score.
- Avoid Highly Processed Foods: Avoid 'instant' or 'easy cook' foods, because these tend to be more highly processed.
- Choose the Right Varieties: Choose amylose-rich basmati rice instead of other varieties of white rice. Use new potatoes instead of old and boil in their skins rather than mashing, baking or chipping.
- Combine Foods Wisely: Always combine protein like fish, chicken and dairy with carb-rich foods like bread, potatoes and pasta. Pairing low GI carbs with a healthy source of fat and protein (such as olive or coconut oil, eggs, and fish, for example) can be helpful for managing blood sugar levels, energy and hunger.
- Focus on Whole Foods: Eat as close to nature as possible. You should avoid processed foods because they contain artificial ingredients and preservatives.
- Balance Every Meal: Balance every meal with healthy fats, healthy proteins, and healthy carbs. A meal plan is your guide for when, what, and how much to eat. Your plan will help make sure you get the nutrition you need while keeping your blood sugar levels on target.
- Portion Control: Portion size and serving size aren't always the same. A portion is the amount of food you choose to eat at one time. If you're eating out, ask for half of your meal to be wrapped up to go so you can enjoy it later. At home, measure out snacks; don't eat straight from the bag or box. At dinnertime, reduce the temptation to go back for seconds by keeping the serving bowls out of reach.
Foods to Include in Your Low Glycemic Diet
There are plenty of healthy and nutritious foods to choose from. You should build your diet around the following low GI foods:
- Bread: whole grain, multigrain, rye, sourdough, sprouted bread/grains, whole wheat tortilla, almond flour
- Breakfast cereals: steel cut oats, bran flakes
- Fruit: apples, strawberries, apricots, peaches, plums, pears, kiwi, tomatoes, blackberries, blueberries, cherries, cranberries (whole), coconut, cucumber, grapefruit, passion fruit, prunes, raspberries, tangerines
- Vegetables: carrots (raw have the lowest glycemic index), asparagus, artichoke, broccoli, cabbage, cauliflower, celery, eggplant, garlic, greens, leeks, peppers, mushrooms, okra, onions, radishes, spinach, squash, turnips, zucchini
- Starchy vegetables: sweet potatoes with an orange flesh, corn, yams, winter squash
- Legumes: lentils, chickpeas, baked beans, butter beans, kidney beans, black-eyed peas, black beans, green beans, hummus, pinto beans, lima beans, navy beans, peanuts, snap peas, snow peas
- Pasta and noodles: pasta, soba noodles, vermicelli noodles, rice noodles, whole wheat pasta, hearts of palm noodles, shirataki noodles, lentil pasta, chickpea pasta
- Rice: basmati, Doongara, long grain, brown, black rice
- Grains: quinoa, barley, pearl couscous, buckwheat, freekeh, semolina, bulgur, farro, rolled oats, steel-cut oats
- Dairy and dairy replacements: milk, cheese, yogurt, coconut milk, soy milk, almond milk, plain cottage cheese, plain kefir, plain yogurt, unsweetened almond, coconut, soy milks
- Fish and seafood: including salmon, trout, tuna, sardines, prawns
- Other animal products: including beef, chicken, pork, lamb, and eggs
- Nuts: such as almonds, cashews, pistachios, walnuts, macadamia nuts, hazelnuts, pecans
- Fats and oils: including olive oil, butter, avocado, chia seeds, flax seeds, hemp seeds, olives, avocado, coconut, olive oils, pumpkin seeds, sunflower seeds
- Herbs and spices: such as garlic, basil, dill, salt, pepper, all-spice, cardamom, cinnamon, cayenne pepper, cumin, paprika
- Non-starchy vegetables: such as broccoli, cauliflower, celery, and zucchini
- Quality protein: Animal proteins are also a zero GI/GL food group, containing very little or zero carbs.
- Allulose, Monk fruit, Stevia
Foods to Limit or Avoid
Nothing is strictly banned on the low GI diet. However, try to replace these high GI foods with low GI alternatives as much as possible:
- Bread: white bread, bagels, naan, Turkish bread, French baguettes, Lebanese bread
- Breakfast cereals: instant oats, Rice Krispies, Cocoa Krispies, Corn Flakes, Froot Loops, instant oats, processed cereals such as corn flakes, froot loops, etc.
- Starchy vegetables: Désirée and Red Pontiac potato varieties, instant mashed potatoes, potato (baked, mashed), frozen or canned corn, parsnips
- Pasta and noodles: corn pasta and instant noodles
- Rice: Jasmine, Arborio (used in risotto), Calrose, medium-grain white, white rice and brown rice: however, the GI score depends on many factors including cook time, grain size, and preparation methods.
- Dairy replacements: rice milk and oat milk
- Fruit: watermelon, dried dates, pineapple, overly ripe banana
- Savory snacks: rice crackers, Corn Thins, rice cakes, pretzels, corn chips
- Cakes and other sweets: scones, doughnuts, cupcakes, cookies, waffles, cakes
- Other: jelly beans, licorice, Gatorade, Lucozade
- Fruit juice with added sugars
Sample Meal Plan
This sample menu shows what 1 week on the low GI diet might look like. Feel free to adjust this or add low GI snacks based on your own needs and preferences.
Monday
- Breakfast: oatmeal made with rolled oats, milk, pumpkin seeds, and chopped, fresh, low GI fruit
- Lunch: chicken sandwich on whole grain bread, served with a salad
- Dinner: beef stir-fry with vegetables, served with long grain rice
Tuesday
- Breakfast: whole grain toast with avocado, tomato, and smoked salmon
- Lunch: minestrone soup with a slice of whole grain bread
- Dinner: grilled fish served with steamed broccoli and green beans
Wednesday
- Breakfast: omelet with mushrooms, spinach, tomato, and cheese
- Lunch: salmon, ricotta, and quinoa cups with a salad
- Dinner: homemade pizzas made with whole wheat bread
Thursday
- Breakfast: smoothie with berries, milk, Greek yogurt, and cinnamon
- Lunch: chicken pasta salad made with whole wheat pasta
- Dinner: homemade burgers with beef patties and vegetables on whole wheat rolls
Friday
- Breakfast: fruity quinoa porridge with apple and cinnamon
- Lunch: toasted tuna salad sandwich on whole wheat bread
- Dinner: chicken and chickpea curry with basmati rice
Saturday
- Breakfast: eggs with smoked salmon and tomatoes on whole grain toast
- Lunch: whole grain wrap with egg and lettuce
- Dinner: grilled lamb chops with greens and mashed pumpkin
Sunday
- Breakfast: buckwheat pancakes with berries
- Lunch: brown rice and tuna salad
- Dinner: beef meatballs served with vegetables and brown rice
Healthy Low GI Snack Ideas
If you find yourself hungry between meals, here are a few healthy low GI snack ideas:
- a handful of unsalted nuts
- a piece of fruit like apple slices with nut butter, almond butter, or peanut butter
- carrot sticks with hummus
- a cup of berries or grapes served with a few cubes of cheese
- unsweetened Greek yogurt with sliced almonds
- a hard-boiled egg
- low GI leftovers from the night before
Tips for Success
- Transform Your Kitchen: Stock Up on Low Glycemic Staples: Fill your pantry and refrigerator with nutrient-rich, low glycemic foods. Focus on whole grains, fresh fruits and vegetables, lean proteins, and healthy fats. Clear Out Temptations: Bid farewell to processed snacks, sugary treats, and unhealthy convenience foods. Removing these tempting items from your kitchen reduces the likelihood of indulging in empty calories. Organize Your Kitchen: A well-organized kitchen makes healthy choices effortless. Arrange your cooking utensils, pots and pans, and food storage containers for easy access. Equip Yourself with the Right Tools: Invest in quality kitchen tools that support your low glycemic cooking endeavors.
- Meal Prep: Meal Prep Like a Pro: Set aside dedicated time each week to plan and prepare your meals in advance.
- Explore Recipes: Get Creative with Low Glycemic Recipes: Explore the vast array of low glycemic recipes available and discover new flavors and culinary adventures.
- Start Small: Changing your eating habits can be tough, so I recommend starting small and introducing one thing at a time.
- Don't Give Up: When you feel like you've "fallen off the wagon", go easy on yourself and get back on.
- Stay Hydrated: Drinking plenty of water is key to maintaining healthy body functions. Water flushes out toxins and waste products from the body, helping to keep organs functioning properly.
- Be Mindful of Portions: It's easy to eat more food than you need without realizing it.
Limitations and Drawbacks of the Low GI Diet
Although the low GI diet has several benefits, it also has a number of drawbacks.
Incomplete Nutritional Picture
First, the GI doesn’t provide a complete nutritional picture. It’s important to also consider the fat, protein, sugar, and fiber contents of a food, regardless of its GI. For example, there are many unhealthy low GI foods, such as candy bars and ice cream. Just because a food is low on the index doesn't mean it's healthy. And some high glycemic index foods offer a lot of nutrition. For example, parsnips have a higher glycemic index value (52) than vanilla cake (42).
GI Measures Single Foods
Another drawback is that the GI measures the effect of a single food on blood sugar levels. However, most foods are consumed as part of a larger mixed meal, making the GI difficult to predict in these circumstances.
Doesn't Account for Carb Quantity
Lastly, GI doesn’t take into account the number of carbs you eat. However, this is an important factor in determining their effect on your blood sugar levels. For example, watermelon has a high GI of 72 to 80 and wouldn’t be considered the best option when following a low GI diet. However, watermelon also has a low carb content, containing under 8 grams of carbs per 100 grams. A typical serving should have minimal effect on blood sugar levels. This highlights that using GI in isolation may not always be the best predictor of blood sugar levels.
Can Be Confusing
The glycemic index diet can be confusing. Also, the diet doesn't offer advice on non-carb foods. It's up to you to figure out how many calories and how much fat you're getting each day. And eating some foods in combination -- like a high glycemic index carb with protein and fat, for example -- can affect how much your blood sugar rises.