Fueling for Fitness

By Carla Schuit- MPH, RD, LDN

Between all of the different diet trends out there and research it is hard to sort out what is the truth and what is just fluff. The truth of the matter is your body doesn’t know if it is eating Mediterranean or Paleo. It does know it is eating protein, carbs, fats and many micronutrients. All things that it needs to function daily. We have already discussed previously why your body needs all three of the macronutrients using carbs to fuel your brain and red blood cells and fat for joint health and cell structure. These are both essential nutrients, but when it comes to burning calories and losing weight protein is our best weapon aiding in energy expenditure while preserving muscle or lean body mass.

We all know that by including circuit, weights and resistance training in our work out regimen it promotes the maintenance of muscle, burning of fat and increases our RMR (resting metabolic rate). Every 1lb of muscle increases the resting metabolic rate by about 11 calories, using this energy when not exercising to maintain and repair that muscle.

A healthy weight loss is considered to be 1-2lb a week. In order to accomplish this we would need to create a deficit of 500calories a day either by burning during exercise, consuming less or a combination of the two, as 3,500calories equals a pound.

We can assist this work by consuming the appropriate percentage of calories from fat, carbs and protein.
The RDA (recommended daily allowance) for carbs is a minimum of about 130g of carbs a day to maintain brain function and prevent protein breakdown for glucose. See your brain needs glucose to function and if it is not getting it from carbs it will begin to break down protein.
The 2010 Dietary guidelines provide the below reference ranges for macronutrients.

• Carbohydrates: 45-65% of calories
• Fat: 20-35% of calories
• Protein: 10-35% of calories

The calorie distribution can be more impactful than total calories consumed. By maintaining a calorie level and adjusting protein, carbs and fat we can promote or slow down fat loss and muscle synthesis. Keeping in mind that the optimal protein absorption at one time is 30g, so it really doesn’t do our bodies good consuming loads of protein in one setting but spreading it out evenly through out the day. This will also prevent hunger and promote satiety.

Because of this special function of protein for active people or those looking to lose weight but maintain lean body mass I recommend higher percentages of protein, lower fat and lower carb. No foods are mono-nutrient meaning that most will contain all three or at least two of the macronutrients. I recommend to track meals in fitness apps like MyFitnessPal to see how daily meals are divided between the different nutrients. People often eat healthy foods but in higher portions, such as nuts which are good sources of protein but high in fat, that throws of their macronutrient balance.

When translating nutrients to foods choose whole complex carbs such as sweet potatoes and whole grains, proteins should be lean and fats of plant origin.
For your specific macronutrient requirements contact myself or your local Registered Dietitian.

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