Protein vs. Fiber: A Civil War

Praveen Budhrani
Praveen Budhrani

 | 1 minute to read
Nutrition

In the recent times, there has been lot of discussions being done on effects of dietary fiber on protein absorption in our body.

Protein is known to everybody; Protein is the most important macro nutrient. Proteins are broken down into amino acids to perform functions like (i) Muscle and enzyme synthesis, (ii) hormone production, (iii) fluid balance, (iv) Growth and tissue maintenance and many other important functions. So, basically for our area of interest, we can easily say “no proteins = no gains”. On the other hand, dietary fibers are a type of carbohydrate that cannot be digested by our body, they go into our digestive tract, depending upon whether it is soluble or insoluble fiber, they are accordingly processed in our body. Fiber although doesn’t play any direct role in achieving optimum body composition but is important for smooth bowel movements, providing feeling of fullness without giving extra calories and most of the fiber rich foods are rich in micro nutrient profile. Over the period of last decade, there has been several studies being done on rats, pigs and humans, analyzing the role fiber on protein digestibility and most of these studies have produced conflicting results. Like one of the recent study published by Davd J. Baer in 2014 found that fermentable and viscous fiber (pectin and guar gum), decreases the digestion of protein more than non-viscous and non-fermentable fiber (cellulose), which means that having beans and legumes (soluble fiber) can do more harm to protein digestion when compared to their insoluble counterparts like wheat bran, whole grains etc. having said that, the sample size of study was just 15 people (including one drop out) and it was a self-reported study. With such a low sample size and self-reporting mechanism among the samples, there may be possibility of lack of data integrity (https://academic.oup.com/jn/article/144/7/1023/4569759) Another three research performed on rats found Protein Efficiency Ratio (PER) to be considerably high (https://academic.oup.com/jn/article/146/4/737/4584906) , Low (https://www.eijst.org.uk/…/front…/gallery/Vol._2_No._9/2.pdf) and Unaffected ( https://academic.oup.com/fqs/article/1/1/47/4791730 ), when feeding with insoluble fiber as compared to free fiber sources, thereby making outcome of fiber consumption on protein digestibility little unpromising and of course studies although might be well controlled ones but they were performed on rats and might produce different results when performed on humans . While there are many studies performed, as a combined view in a paper published by Seidu Adams and Colleagues concludes that dietary fiber and fiber rich diets especially soluble fiber (like legumes, beans and even some fruits and vegetable) does seems to decrease protein digestion. (https://www.mdpi.com/2079-6439/6/2/29/htm…) Conclusion: While will always be certain methodological limitations in all the studies performed and also the extent of decrease digestibility is something which requires more deeper understanding. As a practical takeaway, while the benefits of fiber consumption are well documented and well received by the fitness community, however as a general practice, I recommend to keep fiber intake close to minimum recommendation of 10-15mg for every 1000 calories and avoid very hypo calorie diets, which makes you dependent on high fiber foods for satiety. Cheers, Praveen Budhrani #Fittr #FittrCoach

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