Acidic Diet: It May Prevent You From Achieving Your Optimal Body Composition

Many people now understand that weight loss does not only mean seeing the number on the scale decrease.  People also understand that weight loss is not only seeing your body mass index (BMI) go down as well.  While weight and BMI can be useful markers, we now know that achieving optimal body composition is most important.  In other words, what is the ratio between your lean mass (muscles, bones, organs, etc…) and your fat mass (adipose tissue)?  When losing weight, have you lost your lean mass or your fat mass?  Increasing or preserving lean mass is important as it includes the functional tissue of your body and has a large influence on your metabolic rate.   

Exercising is an important way to ensure that you increase your lean mass while losing total weight.  However, patients come into my office after many months of diligently working out (often with an experienced trainer) and see a lack of change in their fat mass percentage as well as their weight.  As expected, this can be very frustrating.  When I ask individuals about their diet, I usually notice that their diet is very heavy in protein.  This is understandable as it has been repeatedly shown that high protein intake preserves lean mass as well as satiety, both of which are important for weight loss.  However, these high protein diets are usually very low in fruits and vegetables.  The “missing factor” that has not been taken into consideration is diet induced acidosis which can decrease lean mass.

Please note that acidosis is different from acidemia.  Acidemia is when your blood pH is less than ideal (7.35).  Because our body has many compensatory mechanisms to ensure that our pH is stable, acidemia is not very common.  However, acidosis is a process or trend towards acidemia and may be assessed by testing your urine pH.  Examples of acid forming foods include animal proteins and soft drinks.  Examples of alkaline forming foods include fruits and vegetables (Pizzorno et al. 2009).

In fact, a research study in 2008 showed that a “higher intake of foods rich in potassium bicarbonate (bicarbonate neutralizes acids) such as fruit & vegetables, may favour the preservation of muscle mass in older men and women”.  In addition, supplementation of bicarbonate increased lower-extremity muscle performance in women 50 years old and older (Dawson-Hughes et al. 2008).  Bicarbonate supplementation also improved high-intensity exercise performance and anaerobic performance (e.g. sprinting; Bishop et al. 2005).  Therefore fruits and vegetables can help preserve lean body mass and even improve fitness!  To learn more about how diet induced acidosis may affect you long term, please attend our seminar on January 16.