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Nutrition Question & Answer: Calorie Intake

Here is one question that I was asked this past week.

“It has been stated that women should eat a minimum of 1200 calories per day or else their bodies go into 'starvation mode' and their metabolism starts slowing down.  That said, if you are exercising, do you have to net out at 1200 calories (ex - eat 1600 burn 400) or can you eat 1200 and then burn off calories from there?  What is the optimal mix to exercise and lose weight?  Does it include a high protein diet? “

This is a great question. I have been asked this or similar forms of this question numerous times by my clients over the years. There are many parts to this question, and I will try to address them each individually.

First, there is NO magic minimum calorie number, like 1200, below which a person’s body, male or female, goes into starvation mode (meaning a person’s metabolism slows down). Each person however does have a baseline metabolic rate (BMR). Your BMR is the amount of calories your body burns each day from just day to day activities. Your BMR does not take into account extra physical activity like jogging, swimming, or strength training. It only accounts for basic tasks for living, like breathing, digesting food, and other necessary actions. Most people’s BMR can be calculated by multiplying his or her bodyweight in pounds by a number between ten and fourteen. For example, an 150 lb. man would have a BMR of 1500 to 2100 calories per day.

Many people still cling to the old concept that in order to lose weight the calories in (consumed) must be less than calories out (burned through activity). For example, if a woman ate 1000 calories each day while burning off 1500 calories through exercise, then she would lose weight at the rate of 500 calories per day. This idea has been proved to be incorrect on many levels. All calories are NOT equal. For example, the calories your body consumes from fiber, in broccoli, in flax seed, or in an apple, don’t even count as part of your caloric intake. In fact, consuming fiber actually causes your body to expend more calories. Also the macronutrient protein creates what is called a “thermic effect.” After one eats a protein rich food, like chicken, cottage cheese, or salmon, the thermic effect raises one’s metabolism by fifteen to twenty percent,. While 100 calories from fats or carbohydrates may do little for your body’s metabolic rate, 100 calories from protein may cause your body to burn some extra calories.

Getting back to the “starvation mode” question, it is true is that when people place themselves on a prolonged hypocaloric diet, meaning they are consuming a significantly reduced number of calories for a long period of time, their bodies slow down their metabolic rate in order to conserve energy. This is why caloric restrictive dieting is never successful in the long term. First, protein is usually one of the main macronutrients that gets reduced in this type of diet, leading to a loss in the thermic effect of food as mentioned earlier. Second, as one loses weight on a restrictive diet, one constantly needs to keep reducing one’s daily caloric intake to create further weight loss. This is a vicious cycle that ultimately gets broken by the individual going off his or her diet.

In conclusion, there is no “best” mix of caloric restriction and exercise to lose weight. Be wary of anyone who tells you there is only ONE way to get a desired physique or body fat percentage. However, I will offer a few tips to set everyone of the right path towards body fat loss and better health.

Tip #1 – Eat protein with every meal. As discussed earlier the thermic effect of food is something to be put to good use. Many Americans fail at this tip, particularly at breakfast, choosing a bagel, some cold cereal, or coffee and a donut.

Tip #2 – Don’t restrict calories; make better choices. Instead of focusing on eating less calories for weight loss, one should focus on picking healthier foods. Instead of empty calories from white rice, white pasta, and white bread, one should eat more fibrous vegetables and raw fruits. One should eat more fish and nuts since the healthy fats found in them have also been shown to improve your body’s metabolic rate.

Tip #3 – Strength train. Don’t just jog, walk, or swim. Include strength training as part of any exercise program. Besides making your body stronger, which will make everyday tasks easier, weight training also will help your diabetes, high blood pressure, high cholesterol, and bone density.

I could include more tips, but I don’t want to overload everyone with information. Rest assured I will tackle many of the topics touched on in this response in future Doctor Of Fitness articles.