Still to this day there are so called fitness "experts" claiming that weight loss is just not possible without "clean carbs".
Does a better version of carbohydrates really exist? Or does the body not know the difference?
Let's investigate.
SUGAR/INSULIN DOESN'T CAUSE WEIGHT GAIN
As I breakdown scientifically in this article, an insulin spike does not cause weight gain.
What determines fat gain is positive energy balance (consuming more calories than your body burns).
As I have also spoken about before, a calorie is a calorie (you must check it out if you haven't yet!) - but a calorie from protein has a very different effect on body composition and your potential weight gain/loss than a calorie from fat, for instance.
But still, yes, a calorie is a calorie.
SIMPLE AND COMPLEX CARBS - IS THERE ANY DIFFERENCE?
Back in 2011 a study (1) surfaced that put a real dent into the broscience notion of: "You can't lean off donuts bro - sweet potato and brown rice only mannnn."
Firstly, a simple carb has one or two sugars and refers to sugars like fructose, lactose and sucrose.
Complex carbs have 3 or more sugars and are foods like rice, grains, and potatoes.
The study featured 390 participants who were split into 2 groups for 6 months: a diet high in complex carbs and one high in simple carbs.
And what did they find?
No differences in fat loss.
And guess what?
None in muscle retention either.
And as far as markers of health go, they were the same in their effects on blood lipids (blood lipids are mainly fatty acids of cholesterol).
GI AND WHY IT'S EVEN MORE INACCURATE FOR YOU AND YOUR DIET
Simple carbs tend to have a higher GI and complex carbs have a lower GI.
But as you've just learnt, choosing a carbohydrate based on it's GI with fat loss in mind is a scientifically flawed concept.
For a whole heap of further studies into this topic, check out this article on FIT'N'FLEXED about the MYTH OF GI - my evidence goes a lot further than just the one study (and there's more coming below, don't worry!).
It's has even gotten to the point now where the World Health Organisation and the Food and Agriculture Organisation don't like the whole simple v complex carbs issue and have said:
“Terms such as complex carbohydrates and sugars, which commonly appear on food labels, are now recognized as having little nutritional or physiological significance. The World Health Organization and Food and Agriculture Organization recommend that these terms be removed and replaced with the total carbohydrate content of the food and its GI value..."
I'm also excited to tell you that other research has found trained subjects respond more favourably to high GI foods due to their increased insulin sensitivity (2).
So factoring in that GI is not make or break for weight loss and that you the trained subject will be effected EVEN LESS than your average bear........well you can see why worrying about whether your bread is white or brown, or worrying about a little bit of sugar, isn't going to matter at all.
Say you've got 140 grams of carbohydrates to eat everyday as your limit that I've given you in one of my customised diet plans for sure weightloss - this means they can come from either simple or complex sources, providing you do not go over the amount I've set you speific to your personal statistics.
To backup this notion, a study (3) compared weight loss diets with the same energy values and macronutrients (protein fat and carbs) - but ensured one group had a high GI carb intake and the other a low GI intake.
The results?
Again, no difference in fat loss or muscle retention (yipee!).
Furthermore the high GI subjects weren't any hungrier, less compliant or any less full than the low GI group.
They didn't eat anymore either.
WHAT ABOUT THEIR HEALTH MARKERS?
Blood pressure was uneffected as were their heart rates.
Their glucose and insulin metabolism and blood lipids also weren't effected.
Even their bowel movement patterns weren't effected (yeah I know, they really went all out for this one!)
But the one thing that was different was the larger reduction of the LDL cholesterol (the bad type) in the low GI group.
However, not to be worried, a meta-analysis that surfaced years later found that any effects on health depends on their initial state of health in the first place.
So those that were unhealthy in the first place and had a high GI diet, made their health even worse. But those who were healthy and consumed a high GI diet, were fine.
So if you're a diabetic or you're obese, then a low-gi diet may be what you want.
However, if you're in good health and training regulary (remembering that trained subjects have better insulin sensitivity) then a high GI diet won't be a problem for you.
So essentially for most people reading this, what it boils down to is....
....A CARB IS A CARB
And that it is.
But of course, some carbohydrate sources (like sweet potato) will be higher in fibre and micronutrients which is very important for your health and recovery.
I will add though that fructose is metabolised differently to glucose and CAN cause liver fat in very high doses (think 40 bananas worth of fructose in one study).
However, in real world scenarios and especially when counting macronutrients - fructose is paired with glucose to make sucrose (sugar) and is metabolised near enough the same as glucose and therefore liver fat is not something to be concerned about (5).
You'd have to be consuming all your carbohydrate calories from free fructose for this to be a problem - which NO ONE would do (or advise you to do).
I also want to make clear from this article that I'm not saying you shouldn't ever eat low GI foods because it's bro science.
What I'm saying is that a balance between both is great and there's no serious harm in the high GI type as some "experts" will try and have you believe.
If you wish to get, for example, 40 grams of your carbohydrates on any given day from lollies, and you're fit, healthy and aren't obese or suffering from diabetes (even this point is controversial at this stage but that's another article altogether) - then go for it!
The point is it will NOT make you any fatter or unhealthier.
But just don't tell the bros and fitness "experts" any of this.
They'll never believe you!
"Stay Fit, Stay Flexed!"
REFERENCES
(1) Wadden TA et al. A two-year randomized trial of obesity treatment in primary care practice. N Engl J Med. 2011 Nov 24;365(21):1969-79. doi: 10.1056/NEJMoa1109220. Epub 2011 Nov 14.
(2) Mettler S, Wenk C, Colombani PC. Influence of training status on glycemic index. Int J Vitam Nutr Res. 2006 Jan;76(1):39-44.
(3) Sloth B, Krog-Mikkelsen I, Flint A, Tetens I, Björck I, Vinoy S, Elmståhl H, Astrup A, Lang V, Raben A. No difference in body weight decrease between a low-glycemic-index and a high-glycemic-index diet but reduced LDL cholesterol after 10-wk ad libitum intake of the low-glycemic-index diet. Am J Clin Nutr. 2004 Aug;80(2):337-47.
(4) Glycemic response and health–a systematic review and meta-analysis: relations between dietary glycemic properties and health outcomes. Livesey G, Taylor R, Hulshof T, Howlett J. Am J Clin Nutr. 2008 Jan;87(1):258S-268S.
(5) Riby JE, Fujisawa T, Kretchmer N: Fructose absorption. Am J Clin Nutr 1993, 58:748S-753S.
Author
Dayne Hudson