Carbohydrates—Good Food for Your Brain
The misunderstood nutrient
I feel good when I think of carbohydrates, because I know they provide the right kind of fuel for my brain cells. Unfortunately, many people shun them as if they were the plague. The fact is, carbohydrates have gotten a bad rap recently for weight-loss efforts, just like fat has in years past.
What’s more (and what dieters aren’t aware of), the types of carbohydrates you choose can affect your fat-loss progress to a very high degree. So let’s set the record straight with the facts on carbohydrates.
Diet fads seem to come in cycles. Remember when protein was the enemy and carbohydrates were the answer? Now the opposite philosophy is the new big thing. Yet with new findings about lean proteins, along with the Glycaemic Index, it seems that we were only half right on both counts.
The role of carbohydrates
At any given moment the amount of carbohydrates in the adult body is about 300 grams or less. Some of this is in the blood, but most is stored in the liver and muscles as glycogen.
Carbohydrates have many functions; chief among them is to provide (1) energy to carry on the work of the body and (2) heat to maintain the body’s temperature. Glucose, which is formed when carbohydrates are broken down, is the only form of energy used by the central nervous system, even though other tissues also use fats for energy.
Other Things Carbohydrates Do
1. Carbohydrates spare proteins. This means that with carbohydrates on hand the body need not burn protein from your diet or your body tissue (this means muscle!) to meet energy needs.
2. Carbohydrates aid in the manufacture of non-essential amino acids (refer to Chapter 8 on protein).
3. Carbohydrates are required for the complete oxidation of fats. When too little carbohydrates are available, some fatty acids known as ketones accumulate. A high accumulation of ketones is called ketosis, which interferes with the acid/base balance and causes the blood to become more acidic. Eventually, the condition known as ketoacidosis occurs, which can cause brain damage and eventually death. Dehydration is also a common consequence of ketosis because the body loses water-excreting ketones in the urine.
4. All carbohydrates except fibre have 4 calories per gram. fibre is not utilized for energy and therefore does not have a caloric value.
Is your glycaemic response making you fat?
Equal amounts of carbohydrates from different foods (such as sugar, pastas, legumes, and breads) can produce different increases in blood sugar (technically, blood glucose) in a given time. The immediate effect of carbohydrates on blood sugar is ranked on the Glycaemic Index (GI). As blood glucose levels rise, so does insulin, a hormone that helps shuttle blood glucose out of the blood and into the tissue cells to be used for energy. Insulin promotes fat storage—one reason that eating foods high on the Glycaemic Index tends to make you fat. Not only that, after your blood sugar rapidly rises, it will fall again sharply. The fall makes you feel hungry again, which can lead to overeating.
High insulin levels are associated with obesity.
Choosing carbohydrates wisely
Carbohydrates are an essential part of a healthy eating plan. The amount and type of carbohydrates you consume (using the Glycaemic Index as a guide for making healthy choices) will affect your fat-loss efforts.
The fact is, the modern diet is too rich in high-GI carbohydrates (those foods with a GI rating of 70 or higher). Common high-GI foods are cookies, crackers, bakery items, sweets, snack items, and simple sugars—some claiming to be low-fat or healthy! This is one of the major reasons that people are getting fatter and fatter, with Type 2 diabetes now showing up even in children, who will in turn become the next generation of obese adults.
Now is the time for high-profile nutritional education if we are to prevent a future health catastrophe.
It’s never too late
It’s never too late to change unhealthy eating habits. For example, middle-aged people accustomed to diets of high-GI foods can switch to low-GI foods (those foods with a GI rating below 55) and be far less likely to develop diabetes and heart disease. Examples of low-GI foods are fruits (apples, cherries, and pears), dairy products, stoneground or whole-grain products (oatmeal, brown rice, bulgur, and some cereals and breads), beans, and lentils.
Low-GI diets can also help control established diabetes by keeping blood glucose levels down. Low-GI diets also can help you lose weight, may lower blood lipids, improve the body’s sensitivity to insulin, reduce the Glycaemic Index rating of the overall meal, and improve appetite control.
Additionally, low-GI carbohydrates satisfy your appetite without “over-satisfying” your caloric requirement. This idea is discussed in detail in The New Glucose Revolution, a widely acclaimed book on the detrimental effects of high-GI foods.
In the 3-Apple-a-Day GI Diet Substitution List, you’ll find that most carbohydrate foods are given a glycaemic rating. Following are the categories of low-, intermediate-, and high-GI rating of foods:
| Low-GI rating | below 55 |
| Intermediate-GI rating | between 55 and 70 |
| High-GI rating | more than 70 |
Protein (meats, fish, and poultry) and fat (oils, nuts, and seeds) have little to no effect on glycaemic response and play a vital role in keeping the glycaemic response to a high-GI food to a minimum. In other words, you won’t get hungry an hour later.
The vicious circle of high-GI foods
You might have heard that high-GI foods are used to replenish energy stores in endurance athletes. That is true. But for everyone else, high-GI foods are best minimized, since their primary contribution to the diet is empty calories.
In her book Potatoes not Prozac, Kathleen DesMaisons, PhD, writes about people who are unusually drawn to high-GI foods. She says that sugar sensitivity can cause people to consume large quantities of sweets, breads, pasta, or alcohol. These items can trigger feelings of exhaustion and low self-esteem, yet the spike and fall in blood sugar levels causes sugar-sensitive people to crave high-GI foods even more.
This seemingly endless cycle can continue for years, leaving sufferers overweight, fatigued, depressed, and sometimes alcoholic.
The 3-Apple-a-Day GI Diet is right on track
The primary carbohydrates in the 3-Apple-a-Day GI Diet are from low-GI and high-fibre sources. However, you will also find some intermediate- and high-GI sources included in some of the recipes. According to The New Glucose Revolution, mixing a high-GI food with a low-GI food yields an intermediate-GI meal.
Carbohydrate recommendations
The DRI, for both children and adults, is at least 130 grams of carbohydrates per day, based on the minimum needed to produce enough glucose for the brain to function.
The recommendation in the 3-Apple-a-Day GI Diet is that 40 per cent of total calories (which is 1 gram per pound of body weight) come from carbohydrates. This amount of carbohydrates is equal to the protein recommendation to establish your blood sugar levels and provide lasting energy throughout the day.