What is the Secret to Fat Loss?
There have been many concerns about low-carbohydrate/high fat diets and adverse effects on blood lipid levels and cardiovascular risk. These concerns have not been substantiated by the research and in fact, recent studies, including the one below have consistently reported that triglycerides, HDL (good cholesterol), blood pressure and insulin levels were not significantly different or were more favorable for the low carbohydrate groups.
In 2007, there was a study published in the Journal of the American Medical Association (JAMA), comparing four diets and there effect on weight loss and cardiovascular risk factors. It was known as the AZOT weight loss study:
- A (Atkins Diet): 20 g of carbohydrates and unlimited fats and proteins
- Z (Zone Diet): 40% Carbohydrate, 30% protein and 30% fat
- O (Ornish Diet): less than 10% of calories from fat. Exercise and meditation prescribed
- T (Traditional Diet): Restricted calories, 55-60% carbohydrate, fat less than 30% and saturated fat less than 10%. Regular exercise
The results were as follows:
|Group||Weight||LDL Cholesterol||Triglycerides||HDL Cholesterol||Blood Pressure|
As you can see from the summary above, the low carbohydrate, high fat and moderate protein diet had the most favorable effect on fat loss and cardiovascular risk factors.
Why was the LDL Cholesterol elevated?
Not all LDL cholesterol particles appear to be harmful (atherogenic). Large LDL particles, that are elevated by higher fat diets appear to be harmless.
Small LDL particles work themselves into the artery walls, forming plaques. This is important, because high carbohydrate diets lower HDL cholesterol, raise triglycerides and increase small LDL cholesterol- These three effects increase our risk of heart disease.
Why do we get fat?
Insulin is secreted primarily in response to the carbohydrates in your diet to keep blood sugar under control. It also works to facilitate the storage and use of fat and protein. It does this primarily through two enzymes: Lipoprotein Lipase (LPL) and Hormone Sensitive Lipase (HSL).
LPL is on the membranes of different cells. It pulls fat out of the blood stream and into the cells. In men, LPL is higher in the fat tissue around the abdomen and in women, it is higher around the hips and buttocks, hence the reason for different fat distribution in men and women.
HSL is located inside fat cells and works to make us leaner by breaking down triglycerides into fatty acids, which can then be released into circulation.
Insulin stimulates LPL on fat cells, which causes fat to be diverted from the blood stream into the fat cells, where it is stored. Insulin also suppresses LPL activity on muscles and other cells, so sugar is burned instead of fat.
Insulin suppresses HSL, preventing triglycerides from being broken down inside fat cells and minimizing the outward flow of fat cells.
Insulin also turns on a mechanism in fat cells to pump in glucose (carbohydrate), leading to an increase in glycerol. Glycerol bundles together with fatty acids to form triglycerides. This results in more fat storage.
To assure that we have enough room to store all that fat, insulin works to create more fat cells.
Fat and protein have a negligible effect on insulin.
What about energy balance (calories in/calories out)?
Nutrition “experts” continue to base weight loss on the first law of thermodynamics, i.e. if you eat more than you burn off, then you gain weight and vice versa. However, as mentioned in prior posts, this ignores the second law of thermodynamics, which takes into consideration the thermic effect of food, i.e. the calories used up to metabolize foods based on their chemical make-up.
Regardless of which law one chooses to apply to weight loss/gain, the question is, does this accurately explain why we get fat?
Studies have shown that animal’s whose food is restricted, tend to reduce energy expenditure both by being less active and slowing down energy use in cells, thereby limiting weight loss. Once the restriction ends, hunger occurs and more food will be consumed until the earlier weight is attained.
The body is very efficient at self-regulating it’s metabolism.
What about Exercise?
Exercise is good for a lot of things e.g. increasing bone density, muscle development, diabetes prevention, reducing the risk of heart disease, mood elevation, increasing endurance etc.
It is not particularly efficient for weight loss. It’s true that exercise burns calories, but on the flip side, it also makes you hungry, so you eat more.
Aerobic exercise at moderate intensities burns carbohydrates. Once the glycogen (stored carbohydrate) is depleted, it will need to be replaced. People generally crave and eat carbohydrates after they exercise. As mentioned above, carbohydrates stimulate insulin, which can result in fat storage.
Many people use exercise to make up for eating high caloric foods in an attempt to avoid gaining weight. No reasonable amount of exercise can be used to balance that venti caramel frappucino with a double shot of espresso, a shot of sugar free vanilla syrup, and extra whip cream that you plan to have after leaving the gym!
Marathon runners are often skinny, but if you take a closer look, they aren’t very muscular. That’s because aerobic activity burns muscle as well as fat. In time this can affect metabolism. Marathon runners are generally in a state of “fuel burning”. Eventually, they will need to run more to maintain their weight because they become more efficient at fat burning, so burn less of it.
A more ideal form of exercise, because it help with building lean body mass, involves resistance training or high intensity interval types of sprints e.g. jumping rope, running hills or climbing stairs.
A word about Metabolic Syndrome:
The more insulin you secrete, the more your cells become resistant to it. This results in a need for more insulin to keep your blood sugar under control. As you secrete more insulin, your body stores more fat. This can lead to metabolic syndrome: elevated blood pressure, triglycerides and small particle LDL cholesterol, lower HDL (good) cholesterol and glucose intolerance. Eventually, this can result in type 2 diabetes.
Insulin also works on fat cells to release inflammatory chemicals called cytokines. Chronically elevated blood sugar results in oxidative stress leading to advanced glycation end products, which can stiffen arteries and result in premature aging, e.g. wrinkles. There are also links between metabolic syndrome and alzheimer’s disease as well as cancer.
So what should you eat for optimum fat loss and to reduce cardiac risk factors?
- Unlimited non-starchy vegetables e.g broccoli, cauliflower, chard, kale spinach, Brussels sprouts, mushrooms, lettuce , peppers, tomatoes, onions, radishes etc
- A small amount of non-starchy fruit e.g. berries, apples (not grapes or bananas)
- Pasture raised: beef, poultry and pork fed a healthy diet e.g. grass fed
- Wild Seafood e.g. salmon, halibut, cod and shell fish
- Healthy fats e.g. extra virgin olive oil, butter, coconut oil, walnut oil, almond oil and avocado
- Some dairy if you can tolerate it, e.g. Greek style yogurt and cheese
- Raw Nuts and seeds
What not to eat for optimum fat loss
- Sugar and honey
- Breads and cereals
- Potatoes and corn
- Legumes e.g. beans and peas
- All sweets
If are en endurance athlete, you will probably need to eat more carbohydrates to sustain your activities.
If you are a body builder, having a smoothie with some higher glycemic carbohydrates mixed with protein and fat within 45 minutes of a workout can help stimulate insulin in a positive way for anabolic muscle growth.
For more information on using diet for fat loss and exercise to develop the “body of your dreams”, Dr. Lecovin can be reached at Evergreen Integrative Medicine at (425) 646-4747 or through his website: www.old.drgeofflecovin.com