Weight Loss and Body Shaping Chapter 1: Essential Concepts of Energy and Nutrition (Part 2)

3. Protein

It accounts for 15-18% of the human body, and the daily requirement is 0.8-1.2 grams per kilogram of body weight. For athletes and other people engaged in high-intensity physical activity, the requirement is about 2.5 grams per kilogram of body weight.

Amino acids are the basic building blocks of proteins. Proteins are divided into complete proteins and incomplete proteins. Complete proteins, mainly animal meat, contain all the essential amino acids needed by the human body, and 98% of them can be absorbed by the body; incomplete proteins, mainly plant proteins, are 80% absorbable.

There are 8 essential amino acids that the human body cannot synthesize and must obtain from food. There are 12 non-essential amino acids.

Protein also provides energy to the human body; each kilogram of protein produces 4 kilocalories of energy. Protein constitutes tissue cells and participates in tissue repair, regulates physiological functions, promotes growth and development, and influences the central nervous system. It also plays a role in controlling heredity and enhancing the body's resistance. Insufficient protein intake can lead to endocrine disorders, poor digestion and absorption, weight loss, decreased immunity, fatigue, and anemia; excessive protein intake, on the other hand, can result in inadequate protein absorption and an excessive metabolic burden.

During prolonged exercise, it's important to prevent significant protein loss. An effective method is to appropriately increase carbohydrate intake. People participating in fitness activities, especially strength training, have a higher protein requirement, particularly in the initial stages of training, where adequate protein intake is crucial.

4. Minerals

Minerals make up about 5-6% of human body weight, with carbon, hydrogen, oxygen, and nitrogen accounting for 96% of the total. The human body cannot synthesize minerals and must obtain them from food. Although 99% of calcium, 80% of phosphorus, and 70% of magnesium are concentrated in bones, skeletons, and teeth, minerals maintain the body's acid-base balance, maintain the osmotic pressure of intercellular fluid, participate in the metabolism of fats, proteins, and carbohydrates, and maintain the normal function of muscles, nerves, and the heart.

Because the body's energy metabolism level is high during exercise and the body sweats a lot, the amount of calcium, phosphorus, potassium, and iron excreted and consumed in the body increases. Therefore, exercisers should replenish these nutrients in a timely and appropriate manner after exercise to maintain the body's normal metabolic function and physiological needs.

5. Vitamins – Vitamins (Vitamin)

Vitamins, also known as vitamins, exist in trace amounts in the human body, but even small quantities are sufficient to maintain normal growth, reproduction, and health in animals. Vitamins must be actively absorbed and utilized. They play a role in bone and teeth development, relaxing nerves, relieving pain, aiding vitamin A absorption, preventing osteoporosis, and treating conjunctivitis. Vitamin E can delay aging and has effects such as preventing arteriosclerosis and cardiovascular disease, improving immunity, preventing cancer, promoting metabolism, enhancing endurance, improving physical strength and liver detoxification function, and relieving pain. Vitamin K promotes blood clotting, stops bleeding, increases bone density, and promotes ossification.

Aerobics is an important modern way to lose weight and stay fit. Its metabolic characteristics include high consumption of energy and various nutrients, with energy metabolism primarily based on aerobic oxidation. Therefore, to maintain high levels of hemoglobin and respiratory enzymes, sufficient glycogen reserves, and improved athletic performance, the body needs to supplement with a significant amount of vitamins C, B1, B2, E, and other related vitamins.

6. Water

Water is the source of life and is the most abundant component of human tissues, accounting for about 60-70% of human body weight. It plays a very important role in the human body and is an essential nutrient for maintaining normal physiological activities.

Water is widely distributed in the human body; 65-75% of muscle mass is water, and 25% of fat mass is water. Water is mainly stored in intracellular fluid (about 62% of which is water) and extracellular fluid (such as blood, which is over 90% water, as well as lymph, saliva, and fluids secreted by the skin and kidneys). Water participates in metabolic processes, aiding in digestion, absorption, bio-oxidation, and excretion; regulating body temperature and maintaining normal body temperature; acting as a lubricant for organs, joints, and muscles; and maintaining glandular secretions to replenish body fluids.

A person's water requirement is directly proportional to their body weight and energy expenditure. One milliliter of water is needed for every calorie of energy consumed, and 30-40 milliliters of water are needed per kilogram of body weight. Therefore, a 70-kilogram person would need 2100-2800 milliliters of water. Under normal circumstances, the body's water intake and output are balanced. A healthy adult needs approximately 2000-2700 milliliters of water daily, including water from drinking, food, and metabolic processes. Insufficient water intake can lead to concentrated blood, increased viscosity, and impaired blood circulation and nutrient absorption. A loss of 20% of the body's water can be life-threatening. Water intake should be increased in hot, high-temperature, feverish, or physically demanding situations. Drinking water is the direct source of the body's water needs, such as plain boiled water or tea. However, water is also produced during oxidation within the body, and the body can obtain additional water from food, such as rice (15% water) and meat (50% water).

During and after exercise, when the body loses 2-3% of its weight due to sweating, blood volume decreases, which can significantly affect athletic performance. Therefore, it's important to drink water regularly, in small sips. Simultaneously, it's advisable to drink slightly salty water or beverages with a osmotic pressure close to that of blood plasma to maintain the body's water and electrolyte balance. However, for weight loss, water should be the primary source of fluids.