Friday, July 5, 2013

How Many Carbohydrates Do You Really Need?

Eating healthy should be simple, right? It is apparent that the information given to consumers is mixed and inconsistent. A prime example of this inconsistency is found with carbohydrate recommendations. The recommendations for carbs pushed from the government skyrocket to 300 grams a day or more! The USDA pushes 6oz of grains per day for females and 8oz for males. Once we translate ounces into grams of carbohydrates, you will discover that the numbers do not add up to the recommended 45-65% of carbohydrates also pushed by health professionals. Let's delve into this carbohydrate mystery!

Just to start us off, the AMDR is set in place for the macronutrients (carbs, fats, protein) to help prevent chronic diseases. The AMDR for protein is 10-35% and the AMDR for fat is 20-35% (both ranges are for adults).

Version 1 (Acceptable Macronutrient Distribution Ranges)

Let's take a 25-year-old female at 130lbs with a calorie intake of 1800kcals. Activity level is low.
   Grains: 45-65% of calories from carbohydrates
               810-1170 calories from carbohydrates
               To get grams, we divide by 4kcal/g: 203-293g of carbohydrates 


Version 2 (USDA: choosemyplate.gov)
Let's take the same 25-year-old female from version 1.
   Grains: 6 oz. equivalents. 1 ounce of grains is about 15-20 grams (1 slice of bread, 1/2 cup of pasta).
               6 oz x 15-20g/oz = 90-120 grams

Already, a huge inconsistency of 113-173grams! After seeing the whooping difference, my next thought was maybe included in the AMDR are the fruit, starchy vegetable, and dairy groups. Let's see how those groups factor in.

Version 2 (USDA: choosemyplate.gov) + fruit, vegetable, dairy
    Fruit: 2 cups per day. 1 cup of strawberries is 12g of carbohydrates. 1 cup of apples is 15g.
             If there are about 15g of carbohydrates per cup, that leaves us with 30g of
             carbohydrates.

    Vegetables: 2 1/2 cups per day. This number is then broken down into different categories of
                       vegetables to be eaten throughout the week. 1 cup of broccoli is 4g of
                       carbohydrates. 1 cup of green peas is 12g of carbohydrates.  Non-starchy
                       vegetables (broccoli, greens) generally provide about 5g of carbohydrates
                       and starchy vegetables (corn, peas, potatoes) about 15g of carbohydrates per
                       serving.

          If our 25-year-old female is consuming 1 cup of starchy vegetables a day (15grams) and
          1 1/2 cups of non-starchy vegetables per day (10g), her grand total of carbohydrates from
          vegetables would be 25g.

    Dairy: 3 cups per day. 1 cup of milk is 12 grams of carbohydrates.
               1 cup of yogurt is 15-20 grams.
           If our 25-year-old female consumes 1 cup of milk (12g), 1 cup of yogurt (18g) and
           2-ounces of cheese (0g), her total carbohydrates from dairy would be 30g.

    Total Added Carbs: 30 + 25 + 30 = 85g

Now, if we have 90-120g of carbohydrates to start with and we added the 85g we would end up with a range of 175-205 grams. This still doesn't add up to the AMDR of 203-293g!

Version 3 (AMDR Method 2)
Another method used to calculate the grams of carbohydrate is to subtract the protein and fat calories from total calories and use the remaining calories for carbohydrates.
      1800 kcal x 15% = 360 calories from protein, 90g from protein
      1800 kcal x 20% = 360 calories from fat, 40g from fat
      1800 kcal - 720 calories = 1080 calories for carbohydrates, 270grams. This number falls in the
      range of carbohydrates found in the version 1 AMDR.

Both the MYPlate and AMDR are pushed by most (not all) health professionals. Mostly, the AMDR is used to prescribe diets for patients and clients to help them reach a healthy weight and decrease chronic disease. Seems ironic to prescribe excessive carbohydrates to clients or patients who are either suffering from a chronic disease or working to prevent one. Also, studies have shown that a diet full of excessive carbohydrates leads to diabetes, obesity, high cholesterol, and high triglyceride levels. It is time to rethink what you are eating and cut back on the carbohydrates.


http://www.choosemyplate.gov/printpages/MyPlateFoodGroups/Fruits/food-groups.fruits-amount.pdf
http://www.choosemyplate.gov/printpages/MyPlateFoodGroups/Grains/food-groups.grains-amount.pdf
http://www.iom.edu/Global/News%20Announcements/~/media/C5CD2DD7840544979A549EC47E56A02B.ashx
http://nutritiondata.self.com/facts/dairy-and-egg-products/8/2
http://care.diabetesjournals.org/content/15/11/1572.full.pdf

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