Abby Housefield

Written by Abby Housefield


Are You Eating “Bone Robbers” That Are Increasing Your Risk for a Stress Fracture?

Stress fractures are common, frequent, and a highly feared injury among long distance runners.

A sports clinic in Finland evaluated 100 cases involving stress fractures caused by physical exercise. Of those 100 stress fractures, football players and vaulters each represented 3%, orienteering runners 9%, sprinters 10%, skiers 12%, and long distance runners a whopping 68%.

The pathophysiology of a stress fracture can happen two ways: (1) excessive strain on the bones with a buildup of micro-damage without the ability to repair;  or (2) a depressed bone remodeling ability and normal strain. The first situation is seen more often in all types of athletes, while the second is seen with the female athlete triad, a metabolic bone disease, or osteoporosis.

Studies have shown there are a number of factors that play into stress fractures. Some of those factors are controllable, while others are not. The controllable factors are: weekly mileage, terrain, footwear, and nutrition.

Yup, what you are eating could either be part of the cause or prevention of a stress fracture.

Here is a list of some “bone-robbing” foods that may be putting you at a greater risk for a stress fracture.

Bone robbers: Foods that increase your risk of stress fractures

Phosphoric Acid

Phosphoric acid is a cheap, widely available food additive used to acidify foods and beverages, colas in particular. Adding phosphoric acid to food and beverages adds a tangy or sour taste, similar to citric acid. Phosphoric acid is more affordable for companies to use in products than the healthier option, citric acid.

Not only is phosphoric acid used as a food additive, but it is also used in the dentistry field to clean and roughen teeth and as a rust remover for iron, steel, and other metal surfaces.

Regular and diet sodas are currently the main dietary source of phosphoric acid on the market. A study published in the Journal of Clinical Nutrition found, “The mean BMD (bone mass density) of those with daily cola intake was 3.7% lower at the femoral neck and 5.4% lower at Ward’s area than of those who consumed less than one serving cola per month. Similar results were seen for diet cola and, although slightly weaker, for decaffeinated cola.”

Interestingly, when the question about cola beverages causing a decrease in bone density was first studied, researchers just studied the general category of carbonated beverages. In the first studies, they did confirm the decrease in BMD when an individual regularly drank carbonated beverages. This finding led people to think it was the carbonation that was leeching calcium from the bones. As institutions have continued to study this question, as pointed out in the study quoted above, they have found that it is not actually the carbonation of the beverages but the phosphoric acid in soda that causes the loss of BMD. Might I point out, diet soda also caused a decrease in bone density, not only regular soda.

Ways to Break the Soda Habit

  • Drink 10 glasses of water a day to make sure you are completely hydrated.
  • Eat five small meals of quality sources of protein, fat, and carbohydrates to balance blood sugar. Low blood sugar can often cause the cravings for the addictive substances.
  • Drink carbonated water: If it is the fizz or bubbles that you find refreshing, switch to carbonated water with lemon, lime, or other fruit for flavor.


As runners, we often assume we don’t need to worry about sodium intake because we sweat enough with our daily runs. Although daily sweat sessions are beneficial for moving sodium and toxins out of our bodies, with today’s highly processed foods, there is still a tendency for runners to consume too much sodium. High sodium levels can cause calcium to be excreted in urine and sweat.

Every 500 mg of sodium leaches 10 mg of calcium from your bones.  Read labels and limit your sodium intake to 2–3 grams daily.


Each cup of coffee pulls out an additional 40 mg of calcium from your bones. Green tea is the better alternative, with many health advantages over coffee, including the fact that it increases bone mineral density.

Wheat Bran

Surprisingly, wheat bran, a health food of this past generation, is the only food known to reduce the absorption of calcium when eaten at the same time. So, if you are sprinkling wheat bran on your morning oatmeal thinking you are doing  a healthy thing. yet also taking your daily vitamin and mineral supplement at the same time, you are not absorbing the calcium from your daily supplement.

If wheat bran is part of the meal that you take your vitamins with, you may want to move your supplement consumption to two or more hours before or after you eat wheat bran.


Studies have shown that high blood sugar levels increase the risk of fractures. When the body is constantly experiencing a state of high blood sugar, the bones begin to age. The collagen rods get gummed up, and the bones become brittle. Between the combination of phosphoric acid and the sugar in a cola beverage, an extreme blood sugar spike will take place in the body. Soda is an extremely significant “bone robber.”

The four items listed above are unfortunately common in foods found in a runner’s diet: wheat bran sprinkled on the bowl of breakfast oatmeal, thought to be a nutritional boost; a soda and high sugar bar as an afternoon pick-me-up before the run; a large, sodium-laden burrito to fix the hunger pains after a hard workout. We eat these foods without even considering that they may be setting us up for our next injury.

Stress Fracture Treatment Outline

Download our Stress Fracture Treatment Outline inside your Insider Members area.

It’s a PDF with the treatment options for runners with stress fractures.


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Lunt, M., P. Masaryk, C. Scheidt-Nave, J. Nijs, G. Poor, H. Pols, J. A. Falch, G. Hammermeister, D. M. Reid, L. Benevolenskaya, K. Weber, J. Cannata, T. W. O"Neill, D. Felsenberg, A. J. Silman, and J. Reeve. "The Effects of Lifestyle, Dietary Dairy Intake and Diabetes on Bone Density and Vertebral Deformity Prevalence: The EVOS Study." Osteoporosis International 12.8 (2001): 688-98. Print.

Orava, Sakari, Jaakko Puranen, and Lasse Ala-Ketola. "Stress Fractures Caused by Physical Exercise." Acta Orthopaedica 49.1 (1978): 19-27. Print.

Pepper, M. "The Pathophysiology of Stress Fractures." Clinics in Sports Medicine 25.1 (2006): 1-16. Print.

Tucker, Katherine L. “Colas, but not other carbonated beverages, are associated with low bone mineral density in older women: The Framingham Osteoporosis Study 1,2,3.” Am J Clin Nutr October 2006 vol. 84 no. 4 936-942

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3 Responses on “Are You Eating “Bone Robbers” That Are Increasing Your Risk for a Stress Fracture?

  1. A lot of animal products have been shown to decrease bone density (cheese being at the top) due to their acidity. You may want to look into that. Otherwise great and informative article.

  2. l am in recovery of a stress fracture to my left foot . of which happened while running a marathon at 15 miles in, l am going to start my back to running in two weeks, is there a easy back to running program, l also have aching pains to my left my foot. l have found the above information very interesting,

    Kind regards


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