Low-carb diets (e.g., the Zone Diet, the Atkins Diet) are not recommended as the risk of ketosis may occur. Ketosis is the scientific term which describes a condition when a buildup of ketones (free fatty acid bodies) occurs within the blood due to a serious deficiency in glucose. In essence, the body resorts to using fat as its primary fuel source when carbs are not sufficiently available. Sounds good, right? Wrong! This condition will cause a reduction in blood pH level as a result of increased acidity--not a healthy scenerio. Symptoms include headaches, dizziness, nausea, and overall fatigue. Also, the body's fat metabolism slows when carbs are limited because fat burning becomes less efficient. Remember, the body burns fat more quickly when in the presence of carbs.
Low-protein diets (e.g., the Fit-for-Life Diet) are not recommended as the risk of catabolism, or muscle wasting, may occur. In essence, the body resorts to feeding off of its lean body mass (e.g., muscle tissue, bone, skin, etc.) in order to survive when protein is not sufficiently available. Remember, the body does not need muscles to survive. The health of its organs (e.g., liver, kidneys, heart, lungs, brain, etc.) are much more paramount in order to live. A low-protein diet may reduce cellular turnover and thus, decrease the body's ability to renew its cells regularly.
Low-fat diets (e.g., the Pritkin Diet) are not recommended as the risk of malnutrition increases since inadequate fat within the diet will lessen the absorption of fat-soluble vitamins (e.g., vit A, E, D, and K). In addition, there is clinical evidence that blood cholesterol increases when the body is starved of fat in the diet. Increased cholesterol may predispose one to a higher risk of heart attack and/or stroke. Inadequate fat in the diet may also reduce abdominal fat. Sounds good, right? Once again, wrong! Abdominal visceral fat is needed to protect the body's internal organs and cushion them from injury. Finally, a low-fat diet reduces unsaturated fat (healthy fat) intake.
Low-calorie diets are not recommended as the risk of malnutrition increases as calories decrease. Assorted vitamin and mineral deficiencies will develop if this diet is continued for long periods of time. Other problems include catabolism, decreased overall energy, headaches, dizziness, nausea, fatigue, etc. If you do decide to try a low-calorie diet, just try it for a short duration and NEVER eat less than 1200 kcals.
Here are some questions you should ask regarding any of the fad diets you may see:
- Does the diet program integrate physical activity?
- Does the diet program allow for some flexibility (e.g., lifestyle, career)?
- Is the diet program realistic in its fat-loss or muscle-gain timeline? (less than 2-lb fat loss or 1-lb muscle gain per week is recommended)
- Does the diet program encourage good behaviors in place of bad behaviors?
- Does the diet program provide professional support?
- Does the diet program provide a maintenance phase?
Brian Danley, CFT
"Motivation is what gets you started. Habit is what keeps you going."