In addressing the question “does the glycemic index work for weight loss”, I sometimes cite a brief verbal exchange I had with a friend of mine. His wife had long been having a serious battle with excess body fat. She’d recently been able to finally forge a sort of “dietary beachhead” (if you will) in her fight by eating foods that are low on the glycemic index. When he’d told me this, I impulsively responded:
“Consuming foods that are low on the glycemic index doesn’t guarantee fat loss. It boils down to a calories-in, calories-out equation; she has to eat fewer daily calories than she’s using.”
“Yeah”, he answered knowingly. “… And low glycemic foods are usually lower in calories than high glycemic foods.”
I couldn’t argue with that. He didn’t say they are “always” lower in calories, or that high calories are always proportionally correspondent with high glycemic foods. What he’d stated is generally the case; just observe how a half cup of white rice (high glycemic) has about twice the number of calories as the same quantity of oat meal (low glycemic). This might be because oatmeal still has its fiber intact whereas white rice’s fiber has been removed. But that’s a major point in assessing the ‘does the glycemic index work for weight loss’ question: The more processed a carbohydrate food, the more high-glycemic and calorie-dense it generally becomes as its fibrous husk is ditched in favor of creating a food comprised primarily of a sugary content.
And if we consistently choose brown rice over white rice or a serving of oatmeal over Corn Flakes, the after-effect is a major key to the “does the glycemic index work for weight loss” question. The lower glycemic profile of the brown rice or oatmeal will cause carbohydrate digestion to be slower and energy levels to last longer. This typically reduces the chance of hunger pangs that can result in binge eating.
What is the Glycemic Index?
Many people asking “does the glycemic index work for weight loss” might already be familiar with what the glycemic index is and how it works. For those unfamiliar, the glycemic index (GI) is simply a numerical measurement of how quickly each food listed on the GI is converted to blood sugar after it’s eaten. The numbers range from 1 to 100. These numbers are derived from each food’s tendency to cause a blood sugar rise compared with a 50-gram serving of pure glucose (the glucose is represented by 100 on the scale). Any food falling below 55 on this scale is considered ‘low glycemic.’ Foods in the 55 to 69 range are ‘medium.’ Any food items in the 70 and above range are considered ‘high.’ You can check out a good glycemic index chart by clicking the link below:
This can be very useful for individuals with diabetes. What’s debatable is how useful this is for non-diabetics who want to use it for fat loss.
Many proponents of the GI’s use for fat loss believe the insulin spikes from consuming high glycemic foods contribute to the deposit of body fat. Skeptics of this theory believe insulin fluctuation as a factor in body fat accumulation is of relatively little consequence while being produced by too many variables affecting the glycemic reactions of different foods combined at each meal.
Put simply: the glycemic index skeptics might be accurate in adopting an “it’s the calories that count” motto in summing up their take on losing body fat. The glycemic index proponents contrastingly believe that other physiological factors (such as average insulin levels) affect body fat levels.
“Does the Glycemic Index Work for Weight Loss”… or are too many factors involved?
In considering the question “does the glycemic index work for weight loss”, it’s important to realize the array of factors that can affect a food’s effect on blood sugar levels. For example, if a high glycemic food (such as white bread) is combined in the same meal with a low glycemic food (an apple), the respective glycemic index of each of these two foods will partially cancel out that of the other. This puts the glycemic index number of the combined items somewhere between proportional servings of either item by itself. This somewhat complicates the use of the glycemic index for fat loss.
In addition to the combination of different carbohydrate foods affecting each other’s glycemic effects, protein and fat also reduce the blood sugar spiking ability of carbohydrates. If you and I go eat a couple big bowls of steamed white rice for lunch (high glycemic), our respective blood sugar levels might end up shooting out our ears by the time we walk out of the restaurant. But if we combine the rice with a good portion of chicken (protein) and it’s stir-fried in oil (fat), our blood glucose levels end up rising more slowly.
Sometimes a particular food item can have different glycemic index readings depending on its state. A banana will have a medium glycemic number when it’s barely ripe and difficult to peel. As it ripens, it becomes sweeter and is appointed a correspondingly higher glycemic index number. Bananas are high glycemic carbs once they’re overly-ripened.
Complicating matters more is the issue of calorie content. As opposed to my oatmeal example above, brown rice (medium glycemic) compares quite similarly in calorie content to an equal amount of white rice (high glycemic). However, if an avid eater of white rice were to suddenly switch to eating brown rice instead, I’d likely bet on that person losing some body fat. The question becomes: If they lost fat, would it be due to lower average insulin levels caused by the change? Or would it simply be because of a reduced tendency to over-eat because the fiber in brown rice results in slower digestion and longer periods of satiety?
‘Glycemic Load’ and the fat-loss Question
If I allowed myself, I could eat enough food in one sitting that even a low glycemic item like rye bread could spike my blood sugar as if I’d chugged a bottle of molasses. Okay… so I’m exaggerating a little… but not much.
This raises another issue in the “does the glycemic index work for weight loss” question. Not only does the glycemic index of each food matter; the total load factor of blood glucose counts as well. In other words, the absolute amount of carbohydrates consumed can have as much an effect on blood sugar and insulin (not to mention, calories) as the relative levels of each food’s glycemic index reading. So even if you and I go to lunch and make sure we eat only stir-fried brown rice (medium glycemic) with a lot of chicken (protein) – we could still eat a high enough quantity to send our blood sugar levels into the stratosphere.
Bottom Line: ‘Knowledge as Power’… and ‘Knowing Your Body’
Perhaps the ultimate answer to the question “does the glycemic index work for weight loss” lies in the following idea:
“The more you educate yourself about food and understand your body’s unique responses to different food combinations and calorie counts – the more power you’ll have in controlling your body composition.”
If nothing else, the glycemic index is one more tool for understanding food and its effects on the body. I’d say this counts as “working” for losing body fat… however indirectly. I definitely wouldn’t count it as a gimmick unless one attempts to use it exclusively and in the absence of calorie restrictions for fat loss.