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How to Start a Glycemic Index Diet for Weight Loss
Updated on July 27, 2023
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Diet / Weight Loss
How to Start a Glycemic Index Diet for Weight Loss

You might be wondering—is the glycemic index diet just another weight loss fad? 

We asked registered dietitian Elise Harlow to help us understand what a low GI diet is and if it can really help you lose weight. Before you try it out, there are a few things you need to know.

How to Start a Glycemic Index Diet for Weight Loss 2

What is the Glycemic Index Diet?

The glycemic diet promotes foods that have little impact on your blood sugar levels. 

Your meals will largely comprise of low glycemic index (GI) foods. Foods with medium GI scores may also be added to your meal plan.

Calorie counting and portion control aren’t as important to a low GI diet. The quality of the food you eat is what matters more.

What is the Glycemic Index?

The glycemic index is a rating system for any foods that have carbohydrates and how quickly they affect your blood sugar.

The higher the ranking on the glycemic index, the quicker the food is broken down and turned into glucose by the body. Constant increases in blood sugar may not be healthy and often accompanies conditions like diabetes.

The lower the ranking, the slower the carbohydrates increase your blood sugar levels, making it easier to keep stable. Blood sugar spikes don't occur with a lot of low GI foods.

The breakdown is as follows:

  • Low -- 55 or less
  • Medium -- 56–69
  • High -- 70 or greater

Many dietitians recommend focusing on a variety of food with lots of foods low in the glycemic index.

This is why the diet is called the low glycemic diet. It focuses more on low glycemic food to help keep your blood sugar stable.

It's normal for blood sugar levels to fluctuate, but when your blood sugar is constantly at high levels, you may suffer from the following:

  • Damage to the eyes
  • Damage to the kidneys
  • Damage to the blood vessels
  • Constantly thirsty
  • Urinating more often
  • Fatigue
  • Light-headedness

Blood sugar spikes may also, in themselves, cause dizziness and nausea.

Take note that the glycemic index is a tool used by healthcare professionals and not necessarily the only reference you should lean on. Some foods that are high on the index aren't always bad for you. Your blood sugar and body will benefit most from a balanced diet full of a variety of nutrient-dense foods.

Watermelons, for example, have a high glycemic load, but they're not considered bad for you.

It's not just about avoiding high glycemic foods altogether. Remember that how healthy a food is also depends on:

  • How much you eat
  • How the food is cooked
  • How much protein, fiber, and fat the food also contains

Talk to your doctor before starting a low glycemic diet. They may instruct you to start slow or want to ensure your body can make the adjustment.

How Does the Glycemic Index Diet Work?

The glycemic index diet is based on the glycemic index (GI). The system measures the effects of carbohydrates on your blood sugar.1 

Carbohydrates that have a high glycemic load will cause your blood glucose to increase drastically (hyperglycemia). It can lead to diabetes and weight gain.

A low glycemic load diet can help prevent weight gain and diabetes by keeping your blood sugar stable. You need to pay attention to your blood sugar levels to feel your healthiest.

Unlike your typical weight loss diet, the amount of calories you consume isn’t considered. That said, low GI foods tend to contain fewer calories. 

Eating modest food portions is still crucial. This allows you to get adequate nutrition from your meals without gaining excess fat.

Take note that the glycemic index isn't the be-all and end-all when it comes to determining how healthy food is. You should still consult your doctor for any major lifestyle or diet changes and if the low glycemic diet is for you.

Steps to Starting a Low Glycemic Diet

If you want to start low glycemic diet, consider the following steps and tips:

  • Get your doctor's approval and recommendations -- Your doctor will have the best idea on how to proceed and give you expert advice and care when it comes to diets--especially if you've had trouble with weight in the past (or a bad relationship with food)
  • Start slow -- Abruptly dropping all high glycemic foods may surprise you and your body and make you less inclined to follow through so you should start slow and replace high GI foods with low GI ones little by little until you get used to it
  • Incorporate a variety of low GI foods, don't just stick to the same few foods -- Make sure you are still eating a good variety of foods to keep the diet from being repetitive and boring and to ensure you're consuming as many vitamins and nutrients as possible
  • Remember that medium and high glycemic foods aren't necessarily off-limits altogether2 -- You can still have some food high on the index, but do so moderately
  • Avoid excessive calorie counting -- Obsessive calorie counting can lead to breakdowns and exacerbate mental health issues or body image issues--be kind to your body and your progress
  • Note down any changes and food you've eaten -- Whether it's weight gain or loss, keeping track will help you determine if the diet is helping you

Who Can Follow the Low Glycemic Diet?

Most healthy people can follow a low GI diet. Since it doesn’t completely cut out carbohydrates, it may not feel like a big change.

The diet may also benefit people who have diabetes. It can help control your blood sugar level and improve your insulin response.

But if you have other health conditions or intend to lose weight, you should talk to a doctor before switching to a low glycemic diet.

Why Should You Consider the GI Diet?

The GI diet is relatively easier and lower-effort compared to other diets, making it a good place to start if you want to begin your weight loss journey. Paying attention to the glycemic index is often the most difficult part of the diet, and even then, most foods are already laid out on the index.

Not only is it relatively simple, but you also don't have to cut out every single "bad food." As long as you're moderating yourself, you should be fine.

What Are Other Benefits of Low Glycemic Diet?

Your overall health can improve with a low GI diet. Low glycemic diets aren't hard to follow most of the time and have lots of pluses for your blood sugar levels.

Here are some of its benefits:5 

Blood Sugar Control

Low GI foods won’t dump lots of sugar into your bloodstream. This prevents sudden increases in blood sugar, which can lead to hyperglycemia.

Your body digests low GI foods slowly and adds small amounts of sugar to your blood. It is beneficial for people with diabetes.

Steady Energy Level

Low GI foods prevent your energy levels from spiking and crashing later on. This can help you to prevent fatigue throughout the day.

Protects Your Heart

A low GI diet can also be good for your heart. They can help with weight loss, which is great for your cardiovascular health.

Foods You Can You Eat On A Low GI Diet

Low glycemic foods are carbohydrate sources that contain more proteins and fat. They should make up the bulk of your diet. Examples of foods with a low glycemic index are:2

  • Most fruits
  • Carrots 
  • Lentils 
  • Kidney beans 
  • Bran breakfast cereal 
  • Green vegetables

You can also enjoy moderate amounts of medium GI foods, such as:

  • Raisins 
  • Bananas 
  • Sweet corn
  • Pineapples 
  • Oat breakfast cereals
  • Multigrain, oat bran, or rye bread

Foods You Should Avoid On A Low GI Diet

Carbohydrates that cause your blood glucose levels to spike are off-limits. This includes food items that are heavily processed or sweetened.

Some high GI foods to stay away from include:

  • White rice
  • White bread
  • Potatoes

These foods typically lack fiber, which is an important nutrient found in most low GI foods. Fiber can help to balance your blood sugar response when eating carbohydrates.

Can Low Glycemic Diets Help You Lose Weight?

“Many people can lose weight on a low glycemic diet. However, personal results will vary on somebody's medical history, amongst several other factors,” says Elise Harlow, a registered dietitian.

If you follow this diet, your meal plan will contain foods that fill you up and slowly release sugars for energy. This means you won't get hungry quickly.

One study found that a low GI diet can help you lose significant weight. It may even be better than a low-fat diet.3

Most people who follow calorie-restricted weight loss plans are unable to stick to them. After a few days or weeks, they usually go back to eating unhealthy foods.

A low GI diet won’t drastically change your food choices. Low glycemic foods are pretty widely available and not too hard to source. So it may help you sustain your weight loss efforts.4

Is A Glycemic Diet Easy to Follow?

Meal planning is never easy, but a low glycemic diet isn’t too difficult to follow. 

You don't have to give up carbohydrates completely. You just have to swap high GI carbohydrates for lower GI carbohydrates.

This makes it easier to transition to the diet. The key is to replace most high GI foods in your meals with low GI alternatives.

For instance, you can replace white rice with brown rice. It has a low GI and is a healthier way to keep eating the food you love.6

Updated on July 27, 2023
Elise Harlow
Elise Harlow, M.S., R.D.N.
Medical Reviewer
Elise Harlow is a registered dietitian with a Master of Science in Nutritional Sciences. She is the founder of an online nutrition consulting and coaching business.

Elise helps people use the power of food to lead healthier lives. She works with various clients, including those who want to achieve a healthier weight, improve their gut health, lower cholesterol, manage their blood sugar, or balance their hormones.
Jennifer Anyabuine
Jennifer Anyabuine
Content Contributor
Jennifer Anyabuine is a content writer with KnowYourDNA. She has a B.S. in Biochemistry. She has been writing for 2 years. Her focus is women’s health, fitness, mental health, and general wellness.
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