All about fruitarianism with a long-term fruitarian, Lena

"Lean meat" is a misleading term. I noticed many times in conversations that people who think that they eat "proteins" tend to think about this food group as an almost pure protein, a perfect set of essential amino acids. Especially if they consume so called "lean meats." 

In beef (presented as "90% lean meat") - half of the calories are from fat (http://nutritiondata.self.com/facts/beef-products/6193/2). Even in the leanest bird meat approximately the fifth of the energy is from fat, ~18% in the leanest I could find (http://nutritiondata.self.com/facts/poultry-products/704/2).

Digestibility-corrected amino acid score (PDCAAS) of protein in beef is only 0.92, chicken - 0.91(?), and egg whites and soy - 1 or 100% (not that it matters much). Note, that 62% of calories in a whole egg are from fat, and 40% in soybeans. 

Charles Darwin

There is no fundamental difference between man and animals in their ability to feel pleasure and pain, happiness, and misery. 

Food Energy

Food energy is chemical energy that animals derive from their food and molecular oxygen through the process of cellular respiration. Humans and other animals need a minimum intake of food energy to sustain their metabolism and to drive their muscles.

Organisms derive food energy from carbohydrates, fats and proteins as well as from organic acids, polyols, and ethanol present in the diet. Some diet components that provide little or no food energy, such as water, minerals, vitamins, cholesterol, and fiber, may still be necessary to health and survival for other reasons. 

Using the International System of Units, researchers measure energy in joules (J) or in its multiples; the kilojoule (kJ) is most often used for food-related quantities. An older metric system unit of energy, still widely used in food-related contexts, is the "food calorie" or kilocalorie (kcal or Cal), equal to 4.184 kilojoules. 

<>Fats and ethanol have the greatest amount of food energy per mass, 37 and 29 kJ/g (8.8 and 6.9 kcal/g), respectively. Proteins and most carbohydrates have about 17 kJ/g (4.1 kcal/g). 

Conventional food energy is based on heats of combustion in a bomb calorimeter and corrections that take into consideration the efficiency of digestion and absorption and the production of urine. 

Fruitarians.net Apple