Diet Myths Busted
The Diet FItness Diva Newsletter Archives

I understand that when you do cardio exercise in the aerobic zones (moderate heart rates) you are mostly burning fat to create energy. When you exercise in anaerobic zones (high heart rates) you are mostly burning sugar. What is happening in your body when you are burning sugar? Are you using up your energy supply? 

You are always burning sugar and fat when you work out. When working out in an aerobic zone you burn mostly fat and when you work in an anaerobic zone you are burning mostly sugar (also known as glycogen). You store approximately 119 hours of stored fat but only about 90 minutes of glycogen or sugar. When you work out anaerobically for long periods of time you use up glycogen but do not tap into a lot of your fat stores. At the end of an anaerobic workout, you are fatigued and need to replace the glycogen stores you used up; however, you have fat stores that have still not been utilized. This is why you see a lot of people in the gym that beat themselves to a pulp but do not change their body shape.

When you workout in endurance zones or aerobic zones you burn mostly fat and the resulting weight loss changes the shape of your body. When you workout in zone 4 or anaerobic zones (without oxygen), you burn sugar and increase your cardiovascular limits. You should only work out in anaerobic zones about 20% of the time. That way you eventually increase your anaerobic threshold thus increasing your ability to burn fat at more intense and higher heart rates.

The terms "aerobic" and "anaerobic" refer to the presence and absence of oxygen, respectively. Most of our cells prefer to get their energy by using oxygen to fuel our metabolism. During aerobic exercise with adequate fuel in the form of stored fat, plus oxygen, muscle cells can contract repeatedly without fatigue. During higher intensity exercises that are anaerobic or non-oxygen fueled, muscle cells must rely on other reactions that do not require oxygen to fuel muscle contraction. Burning sugar does not require a lot of oxygen. This anaerobic metabolism in the cells produces waste molecules that can impair muscle contractions. This deterioration in performance is called fatigue.

Fatigue causes you to experience added discomfort and weakening muscles which forces you to slow down and lower your exercise intensity. Slowing down allows the muscles to once again rely solely on aerobic metabolism, burning mostly fat, and supports the removal or chemical conversion of waste molecules.

So how do these terms relate to you? It all depends on your exercise goals. Most of us are non-competitive or non-elite active individuals.We just want to exercise to gain health benefits, feel good and possibly lose weight. Aerobic exercise conditions enable you to exercise for long periods of time, potentially benefiting from the sustained energy expenditure or calories burned. Aerobic exercise tends to be less stressful to muscles, joints, and your heart, which may be important for individuals with arthritis, heart disease, or high blood pressure. However, to more rapidly improve your exercise capacities, tolerance, and performance, some anaerobic exercise training is a necessity.


Sometimes I don't have time to eat much during the day, so I am really hungry at night. I am trying to lose weight. Is it harmful to eat a lot at one time, and to eat after 8 or 9 pm?

It is important to start the day with a wholesome breakfast. It can be yogurt and fruit, whole grain cereal with fruit and milk, or a hardboiled egg with fruit and toast. Choose something that provides a good balance of protein, fat and carbohydrate. Studies show that people who eat a nourishing breakfast are more successful at losing weight and keeping it off. So invest in yourself by investing enough time to have breakfast!

During the day, bring a wholesome lunch as well as a piece of fruit or a hardboiled egg  or a small bag of nuts as a snack for later in the day. If you are hungry at 8:00 PM, then by all means, eat but make it a small dinner. Again stick to natural sources of foods and keep the macronutrients of fats, proteins and carbohydrates in your dinner balanced. If you starve yourself through the day and then come home ravenous at 8 or 9 at night, you run the risk of eating much more than you need because you will eat too much too fast. When people eat this way, by the time the brain gets the message that the stomach is full, you have eaten much more than your body requires. The bottom line is, eat when hungry, stop when you feel satisfied instead of when you feel full. To lose weight, keep the calories you take in lower than the calories expended. It doesn't really matter WHEN you take in those calories, it matters more how many you take in and what the food sources are.


I eat lots of Granola Bars. These are good for you and help lose weight right?

While granola bars sound healthy, many are made with high fructose corn syrup and use trans fats and chemicals as preservatives.  Many are a densely packed food, so a small bar contains a lot of calories and the calories are often not from good nutritional sources.  Homemade granola bars are a healthy alternative to the store bought variety, but they will still have a large number of calories for their size.  As long as you understand that granola bars are a high calorie food item and many tend to be more like a candy bar than a health food, having one for an occasional snack won't hurt you.  If you are really interested in granola bars as an occasional healthy snack, look for bars that:

  • contain five grams of fat or less. Bars with nuts (a source of healthy fats) are OK for up to eight grams of fat.
  • have three or more grams of fiber, or look for whole grains listed as the first ingredient.
  • have a total of two hundred calories or less. For active kids, up to 250 calories is OK, as long as the bar contains nuts and whole grains.
  • do not have any trans fats, added sugars or chemical preservatives.

    As long as you keep your total calorie intake below your total calorie expenditure, you will lose weight.


    I have extra fat on my thighs and belly. If I do leg lifts and sit-ups can I firm up those areas and lose the fat?

    First, please understand that you can not spot reduce. Women tend to carry extra weight around the lower part of their abdomen and their thighs. Men tend to carry extra weight around their bellies. The only way to reduce the extra fat in these areas is to engage in cardiovascular exercise, also referred to as aerobic exercise. Aerobic exercise forces your body to use lots of oxygen as fuel and oxygen helps us to burn fat all over our body. The more oxygen you use during exercise, the more fat you will burn, the more calories you expend. Leg exercises and sit-ups will help tone and firm muscles in those areas but will not burn the fat that covers them.


    I eat a lot of cheese in order to get protein since I don’t eat a lot of meat. I also need to lose weight. Is this ok?

    The protein in cheese is of a high quality and contains all the essential amino acids required by the body for optimum growth and cell repair. However, the downside is some cheese contains high saturated fat levels so for weight loss it would be best to keep cheese portions small. While fat is one of the macronutrients, like any other food source, if you consume more than you need, you will not lose weight. To keep the balance between weight loss and protein intake, it might be better to consume leaner sources of protein like tofu, eggs, peas, beans, lentils or select choices of fish or poultry in combination with smaller portions of cheese.  This way you will still have the cheese you love and the protein you need without consuming more fat than your body can use.