The three main pieces of the metabolism pie are BMR (Basic metabolic rate), TEA (Thermic effect of activity), and the thermic effect of food (TEF), also known as diet-induced thermogenesis (DIT).
This represents the body’s processing of food, including “the digestion, absorption, transport, metabolism, and storage of energy from ingested food.” It contributes approximately 10-20% to the daily total energy expenditure.
Thermogenesis takes place when a portion of dietary calories in excess of those required for immediate energy requirements are converted to heat rather than stored as fat. Some types of obesity may be related to a defect in this mechanism since thermogenesis is directly related to the metabolic rate.
Diet induced thermogenesis (DIT) can be defined as the increase in energy expenditure above basal fasting level divided by the energy content of the food ingested and is commonly expressed as a percentage.
Diet induced thermogenesis is related to the stimulation of energy-requiring processes during the post-prandial period. The intestinal absorption of nutrients, the initial steps of their metabolism and the storage of the absorbed but not immediately oxidized nutrients.
Most studies measure diet-induced thermogenesis as the increase in energy expenditure above basal metabolic rate.
Generally, the hierarchy in macronutrient oxidation in the postprandial state is reflected similarly in diet-induced thermogenesis, with the sequence alcohol, protein, carbohydrate, and fat. A mixed diet consumed at energy balance results in a diet induced energy expenditure of 5 to 15 % of daily energy expenditure. Values are higher at a relatively high protein and lower at a high fat consumption.
High protein vegetable products like beans are a great choice if you want to keep a satisfactory alkaline-acid balance. A varied intake of high protein vegetable products include wholegrains, peas, nuts, seeds, beans, lentils and vegetables like spinach, broccoli and asparagus.
In conclusion, the main determinants of diet-induced thermogenesis are the energy content and the protein fraction of the diet. Protein plays a key role in body weight regulation through satiety related to diet-induced thermogenesis.
The developing controversy about Dietary Guidelines for protein stems from current perceptions that protein intakes above minimum requirements have no benefit and may pose long-term health risks. These beliefs are largely based on assumptions and extrapolations with little foundation in nutrition science.
- Protein is a critical part of the adult diet: While physical growth occurs only for a brief period of life, the need to repair and remodel muscle and bone continues throughout life.
- Protein needs are proportional to body weight; NOT energy intake: dietary protein should be established first in any diet in proportion to body weight and then carbohydrates and fats added equally determined by energy needs and calorie goals. All in all, an equal amount of the three macronutrients.
- Adult protein utilization is a function of intake at individual meals: Protein is an important part of good nutrition at every meal. Vitamins and minerals can fulfill nutrient needs on a once-per-day basis but for protein the body has no ability to store a daily supply.
- Most adults benefit from protein intakes above the minimum RDA: For most adults, replacing some dietary carbohydrates with protein will help to maintain body composition and mobility, improve blood lipids and lipoproteins, and help to control food intake.
- Protein from vegetable sources are better for overall health than those from animal sources. This was obvious in a recent research conducted by The Harvard School of Public Health where those following a low-carb diet rich in plant protein were 20% less likely to have died of common diseases than those following "regular diets". Those on low-carb high in red meat ended up worse that the ones on regular diets.
Diets with increased protein have now been shown to improve adult health with benefits for treatment or prevention of obesity, osteoporosis, type 2 diabetes, Metabolic Syndrome, heart disease, and sarcopenia.
- Diet induced thermogenesis; Klaas R Westerterp (Department of Human Biology, Maastricht University).
- Thermogenesis: Deliberately Wasteful Energy?; Tammy Thomas, RD, M.Sc. CSCS
- New understandings about adult protein needs; Donald K Layman (Department of Food Science & Human Nutrition, University of Illinois).
- What Is Thermogenesis?; Thermogenesis.org
- Protein, weight management, and satiety; Paddon-Jones D, Westman E, Mattes RD, Wolfe RR, Astrup A, Westerterp-Plantenga M.
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