Macro and Micro nutrients Dar AL Uloom University College Of Medicine Macro and Micro nutrients Gastrointestinal and Nutrition Block (GNT 223) Biochemistry Department 2018/2019

Learning Objectives: Understand the nutritional importance of dietary macro and micronutrients. 2. Identify major dietary sources and RDAs of macro and micronutrients. 3. Evaluate the nutritional quality of proteins, the types of dietary carbohydrates, fibers and fats and their benefits. 4. Discuss the role of macronutrients in causing diseases or conditions such as nitrogen imbalance, diabetes, obesity, atherosclerosis and heart disease. 5. Understand the functions of micronutrients (vitamins, minerals and trace elements) and the diseases due to their deficiencies

Macronutrient: The Building Blocks of the Body Nutrients that provide the body with the calories or energy for the normal growth and development of your body. They are essential for nutritional health and well-being. They are needed in relatively large amounts on a daily basis. Macronutrients include: Carbohydrates= 4 kcal/gm Proteins= 4 kcal/gm Fats = 9 kcal/gm

Carbohydrates: Sources of energy Body’s preferred sources of energy (or calories). Needed in the largest amount (45-65%) of the daily calories. Why? Required for proper functioning of the nervous system, kidneys, heart and other muscles. The only source of energy for red blood cells and the brain. Can be stored in muscles and liver and used later for energy. Complex carbohydrates such as whole grains, fruits and vegetables are high in dietary fiber that helps control cholesterol, blood sugar and bowel function. RDA: 130 grams/day for adults and children.

Good sources of Carbohydrates

Good sources of Carbohydrates

Carbohydrates intake and insulin resistance in type 2 diabetic patients

Proteins – cell growth and health Proteins are important for the following reasons: Promote the growth of body cells–and are particularly important for children, teens and pregnant women. Are necessary to repair body tissues and cells. Strengthen the body’s immune functions. Are responsible for making essential hormones and enzymes. Produce energy when carbohydrates are not available. Protein intake should account for 10-35% of the calories that you consume every day. The exact amount of protein that each person needs depends on his or her weight. As a general rule, each person should eat about 1g of protein for every kg of body weight.

Sources of Proteins Proteins are found in animal foods; plant foods such as legumes and nuts; and, in dairy products.

Sources of Proteins

Nitrogen Balance

Protein-energy Malnutrition Disease Marasmus Kwashiorkor Cause Calorie deprivation. Protein deprivation. Age Children younger than age 1 year After weaning at about age 1 year. Food Intake Breast milk is supplemented with watery gruels of native cereals that are usually deficient in calories. Diet consists predominantly of carbohydrates. Symptoms Arrested growth, extreme muscle wasting and loss of subcutaneous fat, weakness, and anemia. Stunted growth, skin lesions, depigmented hair, anorexia, enlarged fatty liver, edema, and decreased serum albumin.

Fats – concentrated energy sources Dietary fats in the foods you eat provide the greatest amount of energy for the amount of food you consume. They are also important because: Help the body absorb and benefit from fat-soluble vitamins such as Vitamins A, D and E. Improve the taste, aroma and texture of food and also help in digestion. Help maintain healthy skin and hair. Protect internal organs from shock and injury. Act as regulator of the body’s temperature. Fats are an essential part of the diet and should comprise 20-35% of the daily calories that you consume. RDA (gm/day): Total fats: 65, Saturated: 20

Key Sources of Fats

Excess Fat Consumption

Micronutrients Micronutrients such as vitamins, minerals and trace elements are required in smaller amounts mainly in milligram or microgram quantities to ensure normal metabolism, growth and physical well‐being, and act as coenzymes for various biochemical reactions in the body. While macronutrients make up the bulk dry weight of food, micronutrients constitute only 1% to 2% of the dry weight. They do not provide energy to the body rather they help in various body functions such as metabolism.

Vitamins Vitamins are essential organic nutrients, most of which are not made in the body, or only in insufficient amounts, and are mainly obtained through food. When their intake is inadequate, vitamin deficiency disorders are the consequence. Thirteen vitamins are grouped under an alphabetical "generic descriptor" title. These include vitamins A, B1, B2, B3, B5, B6, B12, C, D, E, K, folic acid and biotin. Two types: Water soluble and Fat soluble

Vitamins: Functions, Dietary Sources and RDA The RDA values for majority of micronutrients have been defined that ensures proper intake either from diet or supplements.

Vitamins: Functions, Dietary Sources and RDA

Vitamins: Functions, Dietary Sources and RDA

Vitamins: Deficiency Disorders

Minerals Minerals are inorganic compounds that exist in the body as ions (charged atoms) or as part of complex molecules and have a wide range of physiological functions. At least 17 minerals are required for normal metabolic activities. Depending on how much of them is need, minerals are classified as either macro, micro, or trace.

Minerals: Functions, Dietary Sources and RDA

Minerals: Deficiency Disorders

The macronutrients are the major source of energy for the body whereas micronutrients support the body functions. Malnutrition of macro and micronutrients is associated with a number of diseases and clinical conditions. Various diseases are associated either with malnutrition or excessive intake of these nutrients.

References Lippincott’s Biochemistry, 6th Edition, pp 357-394, Lippincott Williams & Wilkins, New York, USA. Textbook of Biochemistry with Clinical Correlations 6th Edition, pp 1071-1096, Thomas M. Devlin, Wiley, USA.