In order to maintain a healthy weight, it is important to understand the mechanisms that cause weight gain. Once you have an understanding of what causes weight gain, you will be in a position to make the right nutrition choices, and you will be able to avoid being fooled by diet foods or even some foods labeled as healthy that actually cause weight gain.
The first concept to understand is the role of insulin in fat production and which foods trigger this process. The second concept is that it takes fat to burn fat, but this is dependent on consuming the right fats. The third concept is how diet foods sabotage the system and cause weight gain. The fourth concept is how processed foods confuse and toxify the system, causing more weight gain.
The primary function of insulin is to maintain normal blood glucose levels. This is part of a process known as homeostasis, which is the body’s physiologic mechanism to maintain equilibrium and balance within the internal environment. In order to maintain safe blood sugar levels the body must secrete insulin to keep blood glucose between 90 and 135. Too much blood glucose is toxic for the cells and too little glucose causes nervousness, shakiness, light-headedness and ultimately confusion and difficulty speaking. The reason for this is that glucose is the primary energy source of the brain.
Insulin facilitates the transport of glucose to the muscles and the liver where the sugar is converted to glycogen. Glycogen is the body’s first choice of fuel for high-intensity aerobic activity because it is readily available and because it is quickly converted to ATP (adenosine triphosphate) for energy. The body has the ability to store up to 350 grams (about 2,500 calories) of glycogen. Once the storage of glycogen reaches the maximum storage capacity, the excess is converted to fat for more permanent storage.
The critical thing is not just sugar, but how a quickly any carbohydrate is converted to sugar and enters the blood stream. Food is actually categorized by this rate of entry. This is known as the glycemic index. On this scale sucrose (table sugar) is given a 100 rating. The glycemic index is a numerical index that ranks carbohydrates based on their rate of glycemic response, in other words their conversion to glucose within the human body. The glycemic index uses a scale of 0 to 100, with higher values given to foods that cause the most rapid rise in blood sugar. Pure glucose serves as a reference point and is given a glycemic index (GI) of 100. It has long been accepted that simple sugars digest quickly and cause a rapid rise in blood sugar, and so many nutritionists recommend eating more complex carbohydrates—but beware, not all complex carbohydrates are created equal. Some starchy foods like potatoes or white bread score even higher than table sugar on the glycemic index.
Now it sounds like all carbohydrates are bad, which is not the case; carbohydrates are an essential nutrient. The important thing is to reduce the impact of dietary carbohydrate by eating foods on the low end of the glycemic scale. You can also reduce the glycemic index of foods or meals by eating a combination of protein carbohydrates and fat at each meal. Monounsaturated fats found in foods like avocados, almonds and olive oil are especially good because they do not affect insulin or other hormones and they very effectively lower the glycemic index of other foods by slowing absorption. Adding small amounts of fat to each meal also results in the release of certain hormones from your stomach that will help you feel satisfied and reduce the number of meals you need, which will assist you in reaching your ideal weight. This concept is known as glycemic load. Managing fat storage as it relates to insulin means lowering glycemic index by adding protein and good fats to high-glycemic foods. This way you can actually maximize calories by management of glycogen stores. Keep in mind that glycogen stores last for approximately 10 to 12 hours when at rest, which is why breakfast is essential.
It takes fat to burn fat? Remember that you can use protein and fat to lower the glycemic index of foods. That’s because fat slows down the entry rate of carbohydrates into the bloodstream and thereby decreases the production of insulin. Fat also sends a hormonal signal to the brain, telling you to stop eating, which is another way it reduces insulin production. As we have learned it’s excess insulin that makes you fat, and having more fat in the diet becomes an important tool for reducing insulin. The best types of fat are monounsaturated fat, like olive oil, guacamole, almonds and macadamia nuts. Now that we are on the subject of fat burning we can address the question of the fat-burning zone in exercise. There is some truth to the fat-burning zone. The body’s top choices of fuel are carbohydrates and fats. During high-intensity workouts, the body opts for the most readily available source of energy, which is carbohydrate. As the intensity slows the body is able to switch to fat metabolism—this occurs when you are at around 55 percent of maximum heart rate. That does not mean that the ideal workout for fat burning is at 55 percent of maximum heart rate because in order to lose weight and burn fat, the total calories burned is essential. The ideal exercise is a combination of slow, steady work with occasional speed bursts. This maximizes total calorie burn during a fixed amount of time exercising. There is actually a science to fat-burning foods called thermogenics. For example, hot peppers contain capsaicin, which has a slight thermogenic effect, and green tea contains epigallocatechin gallate (EGCG), which provides a slight increase in metabolic rate. There are also certain foods that burn more calories than they contain, resulting in a net calorie burn simply from digestion. These foods include celery, strawberries, grapefruit, lettuce, apples and cucumbers.
One way that diet foods can sabotage the system and cause weight gain is by providing both insufficient calories and nutrition. Insufficient calories can trigger the body into starvation mode, a state where the body’s stress response triggers to save life-sustaining calories by slowing the metabolic rate, or the rate at which calories are burned. This is one of the reasons breakfast is such an important meal. Eating breakfast jump-starts your basal metabolic rate (BMR). Basal metabolic rate is the number of calories your body burns at rest to maintain normal body functions. It is the amount of calories per day your body burns, regardless of exercise. Another adverse mechanism caused by diet foods is carbohydrate craving. A Purdue University study recently released in the journal “Behavioral Neuroscience” reported that rats on diets containing the artificial sweetener saccharin gained more weight than rats given sugary food, casting doubt on the benefits of low-calorie sweeteners. A metabolic byproduct of diet foods containing aspartame is formaldehyde. The liver can detoxify the body from low levels of formaldehyde, but any excess that is not immediately metabolized is stored in the fat cells, particularly in the hips and thighs.
Processed foods are laden with preservatives and artificial ingredients. A well-known artificial flavor enhancer is monosodium glutamate, or MSG. Research has shown that MSG, which is found in most popular processed foods, causes weight gain and obesity in lab animals by damaging the appetite regulation center in the area of the brain known as the hypothalamus, resulting in a disorder called leptin resistance. Leptin is the hormone that controls how much a person feels like eating. It signals the brain that a point of satiation and fullness has been achieved; in other words, it signals the brain that it is time to stop eating. MSG interrupts the leptin signal, canceling out the body’s normal mechanism for appetite suppression. Processed baked goods contain white flour, sugar, salt, artificial flavorings and preservatives. Separately all of these ingredients cause weight gain, and as a group they combine to derail normal metabolism and lead to weight gain, digestive disorders, constipation and mal- nutrition. White flour is made by removing the bran and germ from the grain, in other words by removing the nutritional components and fiber from the grain. The remaining endosperm or white part is further processed by bleaching. Since the fiber is removed, the glycemic index is increased, causing a surge in blood sugar and corresponding spike in insulin, leading to glycogen conversion to fat. Most processed foods, including processed baked goods, contain hydrogenated or partially hydrogenated fats like margarine. Studies published in the “New England Journal of Medicine” link the fatty acids found in hydrogenated or partially hydrogenated fats, which are called trans fats, to atherosclerosis and heart disease. Many European countries have either banned hydrogenated and partially hydrogenated oils altogether or have instituted future dates for elimination of their use in foods.
It all may sound confusing, but really it’s not. Just avoid processed foods, foods with additives and white processed flour foods and enjoy real foods like legumes, fruits and vegetables. In summary, foods to avoid include hydrogenated oil, sugar, high fructose corn syrup (HFCS), wheat, processed soy, margarine (including canola), processed foods, sugar, salt, foods containing chemicals, artificial sweeteners, bread, wheat and crackers. Healthy foods to enjoy include butter, eggs, avocados, raw nuts, olive oil, coconut oil, sprouted grain bread, sweet potatoes, rice, quinoa, fruits and vegetables.
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