Carbohydrates
carbohydrates Sports Nutritionist Eoin Lacey and Jeff Willoughby
www.isinutrition.com
www.studio41.co.nz
What should we be eating for long term health and optimal body composition?
It is one of the main issues of debate in the mainstream public, but however when you look at the research (independent research and not research commissioned by sanitarium) the evidence on how we got to such a bad place nutritionally is clear and what we need to do, is fortunately also very clear.
Lets start from the beginning
Firstly, lets define a carbohydrate (CHO). These are foods that when broken down by the body produce sugar in the blood (blood glucose). There are some CHO that get broken down quickly into blood glucose and then there are some that take a while to get broken down into blood glucose (simple or complex carbs). The point people have to understand is that they all get broken down into blood glucose. Foods that we are talking about here are
- Breakfast Cereals
- Bread and Rolls
- Biscuits and Crackers
- Macaroni products, noodles, spagetti and other pastas
- Rice
- Jellies, Jams and Preserves
- Ice Cream, Cakes, Pies and Candy
- Sauces and Gravies thickened with flour and corn starch
- Beer
- Sweet Wines and Liquers
- Sodas (and all "sweetened fizzy drinks")
- Sugar
List from - Richard MacKarness, Eat Fat and Grow Slim 1958
So it is not so much the factor of a carbohydrate that is the problem, it is the sugar (blood glucose) that all carbohydrates are converted to in the body – whether it be pasta or straight chocolate. that is what is doing the damage.
"the greatest single change in the American diet was in fact the spectacular increase in sugar consumption from the mid-ninetenth century onward, from less than 15 pounds a person yearly in the 1830s to 100 pounds by the 1920s and 150npounds (including high fructose corn syrup) by the end of the century"
Gary Taubes, Good Calories, Bad Calories. 2007
There are two hormones that you need to be aware of. Insulin and glucagon. Insulin is the hormone that helps you store glucose (sugar). Every time you eat carbohydrates the pancreas releases insulin, and it is the insulin that helps the glucose to be stored in muscles to be used as energy, also to be stored in the liver and any excess to be stored as fat. Therefore because insulin acts as a storage hormone, as long as we eat foods that create an insulin response, the body will and quite simply keep on storing fat.
"For many people, higher than desirable levels of the hormone insulin means that fat cannot be "burned" or "released" to any significant degree in the presence of insulin"
Jonny Bowden, Living the Low Carb Life. 2004.
As long as there is glucose in the blood, the body does not have to release fat as energy as there is always enough sugar in the blood. It is glucagon that is the opposite of insulin, if insulin is a storage hormone - then glucagon releases fat in the presence of low blood glucose (a mobiliser hormone). This is why we want low blood glucose (hence low carbohydrates in the diet) so glucagon can go to work and release that fat that has been stored.
Insulin actually prevents fat burning. That's why a low carb diet usually produces more weight loss than a high carb/ low fat diet with the same calorie count.
Jonny Bowden, Living the Low Carb Life. 2004.
"Many human and animal studies have consistently demonstrated that high fat/low-carbohydrate diets consumed for > 7 days decrease muscle glycogen content and carbohydrate oxidation, which is compensated for by markedly increased rates of fat oxidation"
Antonio, Kalman et al, Essentials of Sports Nutrition and Supplements, 2008
What is Insulin Resistance?
The term insulin resistance is referring to the fact that after an amount of time (months or years) of eating a diet that is high in refined carbohydrate, the muscle cells are not as receptive to the insulin that is being released by the pancreas anymore.
"diabetes would appear in a population to any extent only after roughly two decades of excessive sugar consumption"
Gary Taubes, Good Calories, Bad Calories. 2007
Therefore the muscles keep on taking a smaller and smaller amount of glucose from the bloodstream. Therefore the glucose has to be stored somewhere. This is the case scenario of someone eating the same quantities and putting on weight over a period of time. Because their insulin resistance has gone up, the calories are stored as fat (research has shown that this is characterised by fat in and around the mid section).
"Accumulation of fat in the abdominal region is associated with insulin resistance and diabetes"
Antonio, Kalman et al, Essentials of Sports Nutrition and Supplements, 2008
Therefore with someone carrying excess fat around the mid section, eating a low refined carbohydrate diet seems to get far better results than other nutrition plans. It is also important to note that this storage of bodyfat has been correlated to an increase risk of heart disease.
"In a follow up study, we showed that a Very Low Carbohydrate Diet (< 50 grams per day) resulted in twofold greater whole-body fat loss and threefold greater fat loss in the trunk region compared with a Low Fat diet"
Antonio, Kalman et al, Essentials of Sports Nutrition and Supplements, 2008
Weight training and insulin resistance
Weight training plays a huge role in helping the body to deal with insulin. When you weight train, due to the large amount of energy used by the muscular system, the muscles become "hungry" for their fuel source (which is glucose), both while working out and also post exercise during recovery. Therefore you can become up to 30% more insulin sensitive due to weight training. Because of the high contractile element of weight training relative to the low intensity of long continuous cardio, I would always choose weight training over long continuous cardio to improve insulin sensitivity.
Here is a food pyrimid that I believe will truly lead to long term health Ref -
Jonny Bowden, Living the Low Carb Life. 2004. © Eoin Lacey 2011
