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Calculating Nutritional Needs

If you are hoping to see serious changes in your weight and body composition, then nutrition is going to play a huge role.  There are many parts to a solid nutrition plan.  For the purposes of weight gain/loss, we must look at overall energy intake.  A chronic surplus of calories consumed leads to weight gain, while a chronic deficit leads to weight loss.  But most people want to do more than to lose or gain weight.  Most individuals want to gain or maintain lean body mass (muscle, bone, organs, tendons/ligaments, water) while decreasing body fat.  For this, we need to focus on protein.  Nutrition needs to be based on performance goals, the types of activities you enjoy doing, your lifestyle, and your food preferences.  Adherence to a program is huge, so it’s important to pick a nutritional approach that fits within your lifestyle.

Calories: We must first start with calculating caloric needs.  First, determine a good target body weight (TBW).  This should be based on a healthy/realistic body composition range.  For men, this is typically 10-20% body fat, for women it tends to be 18-30%.  A good trainer can help you determine this number/range.  Once you have your TBW, we must determine your activity multiplier.  It is important to be brutally honest here, odds are you are 1 lower than you think.  The multipliers are:

Very Inactive & Older: Multiplier is 8.  This is for anybody who never does anything physical day to day.  They have a long commute, office job, and engage in little unplanned movement from day to day.  They are also over the age of 55.

Very Inactive: Multiplier is 9.  Same as above but for individuals under the age of 55.

Inactive: Multiplier is 10.  This for anyone who while mostly sedentary during the day, does get up and walk around or move several times per day.  This can also apply to someone who doesn’t move much during the day, but has a standing desk.

Moderately Active: Multiplier is 11.  This individual is never sitting for more than 90 minutes straight and moves around several times per day.  They also engage in leisurely activities a few times each week such as walking or casual bike riding.

Active: Multiplier is 12.  This individual sits no more than 60 minutes at a time during the day, and engages in leisurely activity 5-7 days per week.

Very Active: Multiplier is 13.  This is for individuals who have a very physically demanding job such as construction, landscaping, assembly line work, etc.

Hard Gainer: Multiplier is 14.  This is reserved only for those individuals who are trying to gain wait, have a very low body fat percentage (below the norms listed), and has never been able to gain wait.

The final thing we must determine is how many moderate to intense training hours we are going to perform each week.   Again, be realistic.  Don’t count warm up time, and if you think you are going to train 3-4 hours per week, use the low number for weight loss and the high number for weight gain.  Here is what the equation looks like:

(TBW x (activity multiplier + training hours))=estimated caloric needs

Here are two examples to help you work through this:

200lb male, with a target body weight of 185lbs who is inactive, and trains 3 hours/week.

(185 x (10+3))=2405 calories/day

150lb female, with a target body weight of 140lbs who is very active and trains 2 hours/week.  (140 x (13+2))= 2100 calories/day.

Protein:  Now that calories have been determined, we must determine protein intake.  Calories will dictate weight gain/loss.  Protein will help preserve or increase lean body mass.  Protein intake should be set at 0.72 up to 1g per pound of target body weight (TBW).  So, for our 2 examples listed earlier, we would have the following:

200lb male with a TBW of 185lbs.  0.72 x 185= 133.2g

The low end would be 133 grams of protein, and we could go up to 185 grams reasonably.

150lb female with TBW of 140lbs. 0.72 x 140= 100.8g

This puts our low end at 101 grams of protein with the upper reasonable range of 140g.

There are 4 calories in 1 gram of protein.  This will come into play when we set our carbohydrate intake later.   Our male would be targeting 133-185g of protein per day which equates to 532-740 calories coming from protein.  For our female, we have targets of 101-140g of protein each day with 404-560 calories coming from protein:

Fat: Fat is essential for optimal hormonal health and should be consumed from a variety of sources.  There is no good or bad fat (outside of trans fats), we should simply seek a variety of fat sources.  Fats (just like carbohydrates) have a huge healthy range you can pick from based on food preference and tolerance.  Fat should make up 20% of your calories at a minimum, but can go as high as 1g per pound of target body weight (TBW).  Using our previous examples:

200lb male, with a TBW of 185lbs.  Calories projected at 2405/day.   0.2 x 2405=481 calories coming from fat.  There are 9 calories in each gram of fat.  So, we take 481/9=53 grams of fat each day for the lowest possible number.  The upper end would be 185g or 1665 calories from fat.  Our fat range could be 53g (481 calories) up to 185g (1665 calories).

150lb female, with TBW of 140lbs.  Calories projected at 2100/day.   0.2 x 2100=420 calories from fat.  420/9=47 g of fat.  Her low end would be 47g (420 calories from fat) up to 140g (1260 calories from fat).

Carbohydrates:  While carbohydrates are not technically essential in our diet, your brain prefers them for fuel, and intense exercise tends to be best fueled through their inclusion.  However, for the recreational gym goer who trains 2-4 days per week, the amount of carbohydrate intake probably has minimal bearing on progress.  Food preference, as well as how your body tolerates different levels should be your main determinant in setting levels here.  To determine carbohydrate levels, we simply take your remaining calories (after setting protein and fat intakes) and a lot them to carbohydrate intake.  There are 4 calories in 1 gram of carbohydrate.  So again, using our previous examples, we would have the following:

200lb male with TBW of 185lbs.  2405 calories per day, sets protein at 0.72/lb of TBW.  This equals 133g of Protein (532 calories).  This guy loves fat so he sets his fat at 1g per pound of TBW.  This would be 185g of fat (1665 calories).  So 2405-(532+1665)=208 remaining calories.  208/4=52 grams of carbohydrate.  Same guy may also choose to up protein to 1g/lb of TBW.  This would give us 185g protein (740 calories).  Let’s say he loves pasta, bread, etc.  So, he sets his fat to the minimum of 53 grams (481 calories).  In this example we have 2405-(740+481)=1184 calories from carbohydrates.  1184/4=296 grams of carbohydrate per day.  There is an endless combination of macronutrients here.

Conclusion: There are many approaches that can be used when determining nutritional needs.  The most important variable is adherence.  Can you stick to this approach long term?  Data suggests that both very low carbohydrate diets (under 100g) and very low fat diets (under 15% of total calories) are difficult to maintain beyond 6 months.  Do the foods you eat make you feel energized, taste good, and satisfy you?  These are all things that should be considered.  We want to emphasize whole foods, while not avoiding any food group entirely unless you have a proven medical condition.  These equations are to be used to help you set baseline numbers.  For weight loss, we should target 0.5% up to 1.5% body weight lost each week.  For weight gain, we should target 0.25% up to 1% body weight gain each month.  If your rates fall below or above those respective rates, we simply need to increase/decrease caloric intake accordingly.  For help setting your numbers schedule your nutrition consultation by reaching out at jeff@fentonfitness.com or calling 810-750-0351.  Nutrition coaching is available for those that require more education and/or accountability.

-Jeff Tirrell, CSCS, CFSC, Pn1