Introduction
The classification of beans as either carbohydrates or proteins often leads to confusion, particularly among those who rely on these legumes as a primary source of sustenance. This article aims to clarify why beans are predominantly classified as carbohydrates, despite being high in protein, and explores the biological and nutritional implications of this classification.
Classification Standards
Dependence on Individual Nutritionists' Perspectives
The classification of beans as either carbohydrates or proteins can vary widely, depending on who is conducting the assessment. Many nutritionists consider beans to be both due to their high nutritional content, which includes both carbohydrates and proteins. However, the predominance of carbohydrate content in beans often leads to them being more commonly classified as carbohydrates rather than proteins.
Tips from a Vegan Perspective
For vegans, beans are often classified more under the category of proteins because they are a primary source of dietary protein. Indeed, non-vegans typically derive their protein primarily from animal sources or by-products, which is why they may classify beans as a carbohydrate rather than a protein in their diet.
Nutritional Content and Classification
Caloric Source Distribution
The nutritional classification of beans is based on the caloric source distribution. Many plants contain potent sources of both carbohydrates and proteins, but beans, with their high carbohydrate and protein content, fall into the carbohydrate category more frequently. When comparing the caloric content, beans deliver approximately 20 calories from protein and less than 10 from carbohydrates per serving, whereas grains typically deliver less than 10 calories from protein. This makes beans a more superior source of protein, which is why they are often classified as such.
Other Legumes in Context
Some legumes, such as peanuts and soy, largely deliver their non-protein calories as fat, much like many animal-based foods. It is important to evaluate these legumes in the same way when considering their nutritional value. If grains and legumes provide an adequate amount of protein, more concentrated sources of animal protein may be considered excessive.
Metabolism and Protein Usage
Human Protein Needs
Humans only need about 10 calories from protein per day, a quantity far less than what many other apes, which are herbivores, require. The higher protein foods available to humans today were exceedingly rare throughout most of our evolutionary history, and current consumption rates could border on toxicity.
Efficiency in Protein Usage
Only a small portion of the protein we consume can be converted into tissue. On average, we lose up to 1% of muscle per year after the age of 50, regardless of protein intake. The body uses most of the protein we consume for recycling rather than building new tissue. Therefore, any source of protein must be rich enough if virtually all of it can be safely wasted.
Role of Fat and Carbohydrates in Protein Metabolism
Our metabolism requires energy to arrange dietary protein into healthy tissue, which should come from burning fat or carbohydrates, not protein. When we become hypoglycemic between meals, our body can disassemble storage proteins for energy. We burn every bit of protein stored from one meal while awaiting the next.
Concluding Thoughts
Protein is a construction material, not a fuel source. When "experts" advocate for significant protein intake, the body converts the amino acids into glucose and uses them instead of glucose. Fat cells prefer branched-chain amino acids, and the pancreas and liver are adept at using amino acids for energy or converting them into glucose.
Understanding the nutritional classification of beans helps us better manage our dietary choices and ensures we meet our nutritional needs effectively.