Low Glycemic Foods and Weight Loss

Many people looking to improve their health, choose to include low glycemic index foods to control hunger, prevent overeating, regulate blood sugar control, and slim down. Some research studies suggest that a low glycemic diet plan can help you lose weight. But not all of the evidence is consistent and some popular beliefs about low glycemic foods may be wrong.

What Is Glycemic Index?

The Glycemic Index (GI) measures the effects of carbohydrate foods on blood glucose levels. It is believed that foods lower in glycemic index will have a more favorable effect on blood sugar, providing sustainable energy.

However, the idea of glycemic index is not totally foolproof. For example a Snickers bar has a lower glycemic index than watermelon, but for most people watermelon will be a better food choice. That's why it's important to understand other factors that influence blood sugar and satiety, which include portions and the composition of meals and foods.

The Low Glycemic Diet

A low glycemic diet is based on the belief that you can curb overeating and maintain steady energy levels if you choose foods with a glycemic index value of 55 or lower. These are foods considered to be low glycemic foods.

Low Glycemic Foods

When following a low glycemic diet, it is recommended to choose foods on the low glycemic index list more often. It is recommended to avoid higher glycemic index foods, such as white bread, white rice, sweetened sodas, and regular potatoes.

High glycemic foods are those foods with a glycemic index of 70 or above. These foods are believed to make your blood sugar spike quickly, followed by a dip that can cause hunger, decreased energy and a need to eat again.

Sample Low Glycemic Foods List (GI Value of 55 or Less)

• Apple
• Barley
• Cashews
• Full fat or skim milk
• Grapefruit
• Hummus
  
• Lentils
  
• Soy beans
• Yams
  

Low glycemic foods may also include high calorie or high-fat foods like cake, corn chips or a Snickers bar. While some foods have a lower glycemic index (corn chips, cake, Snickers bar) that does not automatically categorize them as superior or nutritious.

Foods that contain protein and fat such as animal proteins and oils have a glycemic index of 0 and most non-starchy vegetables are set to have a low glycemic index. Processed foods often carry a GI symbol to indicate that they have been tested to provide a low glycemic value.

Moderate glycemic foods, like whole grain breads, oatmeal, or brown rice are foods with a glycemic index of 56 to 69.

Concerns and Drawbacks

The problem with eating low glycemic foods for weight loss is that these foods may not actually be better for your diet. Susan Kleiner Ph.D., RD, FACN, CNS, FISSN is the owner of High Performance Nutrition in Mercer, Washington, the author of several books on nutrition and has provided nutritional consultation for professional sports teams, elite and Olympic athletes. She says that the premise on which low glycemic diets are based is wrong.

According to Kleiner, a glycemic index value does not indicate a food's speed of entry into the bloodstream. "Glycemic index measures overall blood sugar over a period of time. You're not getting a rate of absorption from that number," she says, referencing several clinical studies. "It might be a small difference in what we believe, but the small difference calls into question how we use the information."

In addition, Kleiner says that low glycemic foods aren't always healthy or good for your diet. She points out that ice cream is a low-glycemic food, but isn't necessarily a good choice if you're trying to lose weight. Even Crisco, she says, is a low-glycemic food.

And what about foods that carry the GI symbol? Kleiner says that people should be skeptical when they choose foods based on the label. "The GI symbol gives people a sense of security when there's really no justification for it." She explains that some manufacturers are using the GI symbol as a marketing gimmick. "They can add cheap fats to get a lower glycemic value and then get to use the GI symbol on the package." 

Should You Use Glycemic Index?

So what's the best way to choose the best foods if you can't rely on the accuracy of the glycemic index? Kleiner says that people will benefit from eating whole foods that are full of nutrients. Those foods might be low glycemic foods, but not always. And she says that the GI number can add confusion. "I like for people to think about real food and not about abstract numbers," she says.

There are so many variables when it comes to measuring GI that it makes it confusing and sometimes unreliable. For example, The GI of any one food can vary depending on several factors such as cooking, mixing, shape, density, molecular structure, fiber content, and food processing methods.

Kleiner suggests making choices based on nutrient value and common sense. For example, watermelon has a higher GI number than a Snickers bar, but provides better nutrition. "The GI number can sometimes be used by dieters to justify eating less healthy foods like ice cream instead of fruit." 

In the end, the healthiest food for your diet is the food that provides healthy nutrients with less processed fat and empty calories. Glycemic index may not always be the best guide to find those foods.

A Word From Verywell

There is no one diet fits all for everyone. If you feel like choosing foods that are lower in glycemic index helps you to maintain your blood sugar or lose weight, than that's great. However, you may find that not all low glycemic index foods are healthy and not all high glycemic index foods are bad. Whole grains, for example, provide important health benefits and are not low glycemic foods.

If you're not sure which foods to include in your diet and which foods to ditch, invest in an appointment with a registered dietitian to get a comprehensive diet plan for weight loss and wellness.