Search around social media and fitness articles and there is no doubt you’ll see a lot of material saying to stay away from simple carbs and stick to only complex carbs. Complex Vs Simple carbs – The Clash Of The Titans. There is certainly plenty to like about complex carbs as they are typically high in fiber and micronutrients. But does this mean simple carbs will be much more likely to be stored as fat? When it comes to body composition and even overall health, how big of a difference does it REALLY make? That’s what we are going to look at today.
To get a fair argument what we really need is research that uses similar macronutrient protocols. Meaning the study needs to be consistent and control intake of other macronutrients and overall calorie intake. It’s really the only way we’ll know if there was a difference based on the types of carbs eaten. Luckily I was able to track down some that looked into just that.
In a study done by Saris et al. (2000) (1) 398 moderately obese adults were assigned to either a low-fat high simple carb group, a low-fat high complex carb group or a control group. The study went for a total of 6 months and changes in body weight, body composition and blood lipids were measured. At the end of the study there was no significant difference in body weight, body composition or blood lipids between the simple carb group and complex carb group while the control group gained weight.
That may be a pretty shocking result, but simple carbs vs complex carbs is a pretty loose term. One system often used is something called the glycemic index (GI) which is a ranking of carbs on a scale based on how they raise blood sugar after consumption. The lower the GI ranking the slower it is digested and absorbed thus producing a gradual rise in blood sugar and insulin levels while the higher the rating the faster it is digested and absorbed and in turn faster releases. Based on this it is generally considered best to eat mostly low GI foods and avoid their higher counterparts.
Research published in The American Journal of Clinical Nutrition in 2004 (2) looked at the role of GI on body weight, body composition and risk factors for type 2 diabetes and ischemic heart disease in overweight healthy adults. During the 10 week study they split participants into two groups, giving them either high GI or low GI test foods. They matched total energy, energy density, dietary fiber and macronutrient composition. At the end of the study the results showed no significant difference in muscle retention or fat loss and it also didn’t affect blood pressure, heart rate, glucose and insulin metabolism or blood lipids and there was even no difference in perceived hunger between the groups. The only real difference came with a higher decrease in LDL cholesterol in the low GI group.
A similar study published in the International Journal of Obesity (3) investigated if a diet with a reduced GI had effects on appetite, energy intake, body weight and body composition in overweight and obese women. This crossover study had two consecutive 12 week periods in which low GI foods were replaced with high GI foods, matching macronutrient composition, fiber content and energy density. Once again there was no difference in energy intake, body weight or body composition nor was there a difference in ratings of perceived hunger or fullness.
One thing we don’t know is how big of a difference there really was in the GI ratings of the foods, but honestly that doesn’t really even matter because the majority of the time carbohydrates are going to be eaten with other foods with fat and/or protein which will blunt the speed in which it’s absorbed to the point where if there is any difference it’s negligible. Either way it shows it’s entirely possible to change body composition in a similar matter without stressing about simple or complex carbohydrates.
Okay by now I think you get my point. There seems to be good support to show that perhaps high/low GI or simple carbs vs complex carbs don’t make a big difference as long as you hit the numbers required for your diet. I’m not by any means saying you shouldn’t consume plenty of fruits and vegetables and other complex carbohydrates. I’m simply saying you don’t have to be afraid of eating some of the foods typically considered as “bad” (you need to stop thinking about foods as good or bad) especially when consumed in a mixed meal. As long as at the end of the day your total macronutrient consumption is the same, you are golden. Especially when you are matching fiber. Which is something I highly recommend. And is also what we will be talking about next time.