How long does it take to digest meat?
By Glenn King, PhD, R.D., C.N.
Monday, June 16, 2008
We have heard a variety of things concerning the ingestion and digestion of meat, especially red meat. Aside from what I’ve learned in the past 35 years studying nutrition, I’ve done some research over the past several months on this subject. It has been quite fascinating and often humorous. I will list a few of the opinions for your enjoyment. How long to digest meat? -Meat and livestock Australia website says “Less than 4-6 hours to digest meat.” Meat is made up of protein and some fats which are easily digested and generally leave the stomach within 2-3 hours. Meat is fully digested within 4-6 hours compared to the dietary ﬁber found in fruits, vegetables and whole grains, which take more than two days. The human digestive system is well designed to digest a variety of foods including red meat, which contains essential nutrients, like zinc, vitamin B12 and long chain omega-3s (www.mla.com.au). -About 4 days to digest meat and about a day and a half to digest vegetables, says Vistara Parham, RN (What‘s wrong with eating meat?). -It takes about 48 hours to digest meat. Says Prerna Salla, author of In search of the perfect diet. -Meat takes about 72 hours to digest. By WikiAnswers.com -”I’ve heard it takes years for a human to digest meat.” Response: Absolutely false. If it were true, the average person would have an extra 200 lbs of red meat in their gut in just one year. It takes 1 to 3 hours to digest meat depending on how much you chew it and the other foods you take with it, says ExpertAnswerbag.com -It takes a few hours to a day to digest meat, depending on the individual’s GI tract, says TeenHealthfx.com -It takes about three months to fully digest a burger, says a popular Health Radio program. -It takes 24 to 72 hours to digest meat, depending on the person’s digestive tract, state of health, medications taken, what is eaten with it, emotions and other factors. For example, a hamburger sandwich with all the trimmings will take about 24 to 72 hours. Why? It averagely takes that time for most people’s digestive tract to do its job. But, on the whole, one to three days will completely digest, or break apart, the food. Scientists are actually able to measure this by “marking” the meal with a type of dye that eventually colors the feces (semi-solid matter that eventually is eliminated from the body via the anus as a bowel movement), so they can see when the residue of something actually exits the body. Once the food is broken apart into its component parts (the macro-nutrients of protein, fat, carbohydrate, water, and micro-nutrients of vitamins and minerals) the broken down products can then be absorbed into the body. Almost all of this occurs by the time the materials reach the small intestine. So the food that you eat for dinner tonight will be in the form of amino acids (protein), triglycerides and cholesterol (fats) and carbohydrates (mostly glucose), vita- mins, minerals, and water probably by tomorrow evening. Probably some, if not most, of it will also have been absorbed into your body and used in some way. Incidentally, the best resource for getting good nutrition information may not be the radio, TV, magazines, or the internet. For nutritional questions, if possible, talk with a dietitian at your local hospital or health care clinic who has been trained in nutrition. A lot of folks think they are experts in nutrition, but you should look for either a R.D. certiﬁcation or any advanced degrees (like M.S., M.P.H., or Ph.D.) in nutrition or a related subject from a college or university that offers training in nutrition, says Dian Dooley, Ph.D. in Nutrition and Anatomy. Facts Digestibility refers to the proportion of a food that becomes available to the body as absorbed nutrients. Beef is highly digestible. In fact, 97 percent of beef is digestible, in comparison to 89 percent of ﬂ our and 65 percent of most vegetables. However, many people equate digestibility with the length of time a food remains in the stomach. Beef and other protein foods remain in the stomach longer than fruits and vegetables- and consequently provide a feeling of fullness for a longer period of time. The surface area of the small intestine (with thousands of villi and micro- villi projections) is approximately 300 square yards. The contents of the stomach enter the small intestine at different rates carbohydrates ﬁrst, then proteins, and then fats. There are more nerve cells in the digestive system than in the peripheral nervous system. Eating too much cooked or processed foods over time effects the pancreas and inhibits enzyme production. The lack of naturally produced enzymes from the pancreas will effect the ability to properly digest food. Cooked or processed foods is the majority of foods consumed by the average person. This includes, so called, healthy diets. Eating such foods also causes an in- crease in WBC (white blood cell) production (protecting the body from what you’ve eaten) each time you eat. Over time, this reaction can impair your immune system and render it insufﬁcient to effectively ﬁght disease. Meat is not really the issue. It is the dietary habits of the person as a whole and the condition of the person’s health at the time. Dietary history is important as well as the quality of the meat, amount per serving, and frequency of eating meat. Most people have a dietary history that impairs the digestive system to function optimally. I hope this helps resolve some of the myths about meat. In context, this article is to place meat in a proper perspective in ones diet rather than to be for or against meat in the diet.
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