You just ate a couple of hours ago and you’re hungry again. You had a huge plate of Ramen noodles and now you are starved, ready for a nap and don’t feel quite right. These are common feelings that can occur after eating foods with a high glycemic index. Glycemic Index (GI) is a system that ranks food made up of carbohydrates on a 100 point scale based on the impact the food has on blood sugar. The higher the number, the more rapidly the blood sugar spike after consuming it. These rapid rises in blood sugars occur after eating carbohydrates that are easily digestible. In general these are the carbohydrates that have some processing and have been stripped of their fiber like mashed potatoes, white pasta, white rice, puffed rice cakes, pretzels and pulp-less OJ.
High Glycemic Index Foods Cause and Insulin Spike
There are many factors that determine the glycemic index but basically, the more quickly a food is digested and absorbed the more rapid the blood sugar rise. If the serving of carbohydrate is excessive and not eaten with foods that may slow down digestion the rise can be quick. The pancreas senses the sudden rise in blood sugar and releases large amounts of insulin to keep the blood sugars in a healthy range. Insulin helps some of the sugar or glucose be used for cell function but any excess is sent into fat storage and circulates in the form of triglycerides in the blood stream. The surge in insulin can also make blood sugars drop very quickly which can affect the nervous system. This may cause shakiness, fatigue, a headache and even anxiousness. It also can make us feel hungry as a way to signal to our body that we need food to get those blood sugars back up to a better range.
Choose Low to Medium GI Foods For Fullness and Weight Loss
If you focus on foods that are lower in GI then you will avoid the insulin spike that leads to fat storage and hunger. The easiest way to remember this is to think of what I call “the sludge factor”. Whole grains, beans, nuts, fruits and vegetables are the foods that make up the sludge factor. These foods are high in fiber. Have you ever seen what happens to a glass of water when you let Metamucil sit in it for too long? It gets thicker and goes down much more slowly. When you eat foods that are high in fiber, the fiber absorbs the moisture in the digestive track and becomes thicker. Now include some fat, hopefully healthy fat from fatty fish like sardines and salmon, flax seed, olive oil or avocados, and you further prolong digestion which will extend the fullness feeling. Protein also adds to the the fullness factor, slowing down the digestion of carbohydrates. Include some healthy protein found in fish, meats, Greek yogurt, eggs, low fat cheese and even some grains and beans and you have extended the fullness factor even further! That’s why a meal of salmon, a serving of sweet potato or my Three Bean salad and a non-starchy vegetable like broccoli or asparagus will keep you full for four to five hours. It’s also why a breakfast of some scrambled eggs and whole grain toast will keep you fuller longer than a bowl of most cold cereals because they have little to no fiber, fat or protein and deliver way too many high glycemic carbs.
Low Glycemic Index Foods (0-55)
- 100% stone ground wheat
- steel cut or old fashioned oats
- most fruits and non-starchy vegetables
- sweet potatoes, peas, legumes, lentils
- whole grain pasta, converted rice, bulgar, barley
Medium Glycemic Index Foods (56-69)
- whole, rye or pita bread
- brown, basmati, and wild rice and couscous
- quick cook oats
High Glycemic Index Foods (70+)
- melons, pineapple
- white bread, rice cereals, instant oatmeal
- short grain rice
- macaroni and cheese from mix
- saltines, rice cakes, popcorn
Other Factors That Affect Glycemic Index
If there is anything to spotlight how much food is chemistry and therefore healthy medicine when thoughtfully chosen, it is the information in this paragraph. Below are some of the other considerations that impact glycemic index:
- ripeness and storage time – a riper banana has a higher glycemic index than a greener one.
- cooking time – al dente pasta has lower GI than pasta cooked longer.
- variety – converted long grain rice has lower GI than brown rice which has lower GI than white rice.
- processing – mashed potatoes has higher GI than a whole potato.
- cooking method – most steamed veggies have a lower GI than roasted.
- temperature – a cold potato – like in a potato salad has a lower GI than a hot potato.
- food combinations – the presence of fat lowers the GI of the food.
- surface area – a puffed grain like in a rice cake has a higher GI than a grain of rice.
Glycemic Index versus Glycemic Load
To further complicate things, Glycemic Load(GL) is another calculation that takes into consideration how the serving size of carbohydrates affects blood sugars. For example, watermelon has a high GI but a typical serving is a lower GL so it will not cause as much of a spike unless you are eating half a watermelon. Conversely, a huge serving(GL) of steel cut oatmeal(low GI) can have a bigger impact on raising blood sugar than a very small serving of instant oatmeal. So the food portion and the type of carbohydrate both impact blood sugar. Those large boxes of Skittles or Gummy Bears at the movie theater may have no fat but they are going to spike your blood sugar, which will spike the insulin response and only lead to weight gain over time if eating other high GI and GL foods excessively over time. Furthermore, it will leave you feeling hungry, tired and perhaps even a little shaky and irritable. Is the short term pleasure worth the long term impact?
Does all this seem too complex? Again, just visualize the Plate Method that moderates portion sizes while getting all the components of fullness factors along with nutrition. Half your plate should be made up of non-starchy veggies, one quarter of your plate made up of lean protein and the other quarter made up of a starch or carbohydrate. Make that starch a whole grain, a bean salad, brown or converted rice, or a potato and you can get the picture. Choose the right carbs(GI) and the right amount(GL) and make cooking at home fun. Realize that you are worth it and your body will pay it forward. And if you really want that sweet, then at least eat it with a meal when there’s also fiber and protein to create the sludge factor. And then go brush your teeth, lock the kitchen doors and turn out the lights!
Click here to learn more and look up the GI and GL of many foods.