Despite what you may have read on Instagram, carbohydrates are not all bad. Just like protein and fat, you can find good carbohydrates and bad carbohydrates. The best way to distinguish between a good or bad carbohydrate is to look at the impact that it has on your blood sugar levels. Nutrition 101 will tell you that carbohydrates with a low impact on blood sugar levels are considered low glycemic carbohydrates whereas those with a high impact on blood sugar levels are considered high glycemic carbohydrates. The latest research indicates that your body processes low glycemic carbohydrates (think raw leafy greens, chickpeas, broccoli, etc.) differently than high glycemic carbohydrates (think rice crackers and pretzels) which leads to less inflammation and weight gain.
The sugar from high glycemic carbohydrates rushes into the bloodstream at a faster rate than low glycemic carbohydrates, causing the body to produce more of the fat-storing, pro-inflammatory hormone called insulin. Insulin serves as a vehicle to transport sugar from the blood into the cell. When a lot of sugar enters the blood at one time, it can prompt the body to overproduce insulin which leads to higher levels of inflammation and fat storage around the belly. If you produce too much insulin as a result of chronically eating too many high glycemic carbohydrates, your greatest weight loss efforts will feel constantly sabotaged. Eventually many people develop insulin resistance, meaning the body doesn’t recognize the insulin being produced which causes an overproduction of insulin and more belly fat. This can also be the first warning sign of pre-diabetes.
Glycemic Index vs. Glycemic Load
There are traditionally two measurements used to determine whether a food has a high or low blood sugar impact and these include the glycemic index and the glycemic load. Research https://www.ncbi.nlm.nih.gov/pubmed/22727193 demonstrates that diets high in the glycemic load and the glycemic index are associated with a 23% and 13% respective risk of Cardiovascular Disease. A 2014 study published in the American Journal of Clinical Nutrition https://www.ncbi.nlm.nih.gov/pubmed/24787494 found that a low glycemic index/moderate carbohydrate diet is a more effective strategy for weight loss and improved insulin sensitivity than a traditional low fat/high glycemic index diet.
Most people are familiar with the glycemic index which is a concept that was originally created by scientists in 1981. The glycemic index is a measurement of how quickly a specific food releases glucose in the blood compared to 50 grams of glucose. The scale ranges from 0-100 and higher numbers mean that the food causes a quick and sharp spike in blood sugar. While the glycemic index of a food provides valuable information, it does not indicate the true impact that a food has on blood sugar in a real meal like the glycemic load is able to do. The glycemic load is calculated by multiplying the glycemic index of a food with its carbohydrate content—providing information about the quantity and quality of carbohydrates. The Glycemic load tells you how much sugar is delivered to the bloodstream, using a 0-20+ scale which is based on serving sizes, total grams of carbohydrates, and fiber content.
One of the main advantages to using the glycemic load is that it takes into account serving sizes and fiber which is important for slowing down the absorption of sugar. For instance, carrots are thought to be higher glycemic because they have a 39 glycemic index but the glycemic load of this fiber-rich vegetable is substantially lower at a whopping two. A 2008 review http://care.diabetesjournals.org/content/31/12/2281.full of the glycemic index and the glycemic load lists the following foods and their calculated glycemic index and load which is also accessible in a Harvard review http://www.health.harvard.edu/diseases-and-conditions/glycemic_index_and_glycemic_load_for_100_foods . See below for specific examples:
|Food||Glycemic Index||Serving Size||Glycemic Load|
|Bagel, white, frozen||72||70g||25|
|White spaghetti, boiled||58||180g||26|
|Whole grain spaghetti, boiled||42||180g||17|
|White rice, boiled||72||150g||29|
|Brown rice, steamed||50||150g||16|
|Banana, raw, average||48||120g||11|
|Boiled white potato, average||82||150g||21|
|Sweet potato, average||70||150g||22|
Take Away Points to Reduce the Glycemic Load and Promote Weight Loss
- Avoid high glycemic carbohydrates, especially refined grains like white bread, pasta, rice, etc. and added sugars.
- Choose non-starchy vegetables like raw leafy greens, broccoli, cauliflower, cabbage, celery, cucumber, jicama, spaghetti squash, zucchini, and carrots more often than starchy vegetables such as potatoes, parsnips, butternut squash and acorn squash.
- Do not eat unlimited amounts of fruits. While fruit is a great source of nutrients, some fruits such as bananas and dried fruits have a higher glycemic impact. These are ok to eat occasionally but should not be eaten in large quantities.
- Incorporate proteins and fats with every single meal and snack. Instead of having a sweet potato or an apple by itself make a stuffed sweet potato bowl with coconut butter/oil and ground chicken or add a handful of nuts with the apple. Fat and protein are key for stabilizing blood sugar levels, decreasing risk of insulin resistance and promoting weight loss. This is exactly why sugar, not fat, makes you fat.
- Add nuts, seeds and beans to meals for a nutrient-dense source of low glycemic foods.
Brigid Titgemeier, MS, RDN, LD is a functional medicine dietitian nutritionist at the first hospital-based functional medicine center in the country and an adjunct instructor in Cleveland, OH. Brigid is a published author of dozens of articles for U.S. News and World Report, the Huffington Post, Cleveland Clinic Health Essentials, and ivillage. When she’s not working she’s usually in her kitchen experimenting with and photographing new recipes for her blog, Beingbrigid.com. She is completely in her element when she is cooking in the kitchen, practicing yoga, listening to her favorite country artists and relaxing with family and friends.