Why Stop Carbs and Sugars?

December 9, 2018

Some people ask the questions: What happens if I stop eating carbohydrates and sugars? What is the minimum daily carbohydrate intake requirement for health? These answers might not be what you think, and your body can be healthy without these. 

The lower limit of carbohydrate consumption is likely zero, and there are no essential carbohydrates required for living.  According to  the Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (2005), the Recommended Dietary Allowance (RDA) for carbohydrate, considered to be the average minimum amount of glucose needed by the brain or central nervous system (CNS), is 130 g/day for adults and children.

The CNS comprises less than 2% of total body weight, but consumes roughly 20% of the total daily calories.  Historically the brain has been considered the only organ that required glucose as a fuel source, utilizing approximately 100-140 g glucose per day.  However, with ketoadaptation, the CNS reduces the obligatory glucose requirement by approximately 80%, resulting in a true utilization of 20-28 g glucose/d.

However, traditional civilizations (Masai, the Greenland and Alaskan Inuit and Pampas indigenous people) survive on a “minimal amount of carbohydrate for extended periods of time with no apparent effect on health or longevity.” 

Research goes on to state that “In the absence of dietary carbohydrate, de novo synthesis of glucose requires amino acids derived from the hydrolysis of endogenous or dietary protein or glycerol derived from fat. Therefore, the marginal amount of carbohydrate required in the diet in an energy-balanced state is conditional and dependent upon the remaining composition of the diet.”

Endogenous glucose production through gluconeogenesis is approximately 2.8-3.6 g/kg/d, or approximately 210-270 g/d in a 70kg human, far greater than the obligatory requirement of 20-28g glucose/d of the ketoadapted human.

According to the Food and Nutrition Board of the Institute of Medicine, “The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed” (pg. 275).  There is no essential need for dietary carbohydrate, provided that “adequate amounts of protein and fat are consumed.”

Carbohydrates are necessary for metabolism, but it’s not necessary to eat them.  Your body will manufacture the carbohydrates it needs.