Nutritional Biochemistry Lecture Notes PDF

**N** **UTRITIONAL BIOCHEMISTRY** **P** **Prof. Dr Soha Sameh EL-Safety** **Chapter 8 Nutrition and Health** - **Health professionals agree that the overall composition of the diet has an important effect on health.** - **Eating too much fat, sat. fat and cholester...

**N** **UTRITIONAL BIOCHEMISTRY** **P** **Prof. Dr Soha Sameh EL-Safety** **Chapter 8 Nutrition and Health** - **Health professionals agree that the overall composition of the diet has an important effect on health.** - **Eating too much fat, sat. fat and cholesterol and not eating enough vegetables, fruits, and fiber has been linked to an increase in heart disease and other cancers.** - **The federal government constantly revises its official U.S. Dietary Guidelines for Americans to help consumers choose a healthy diet.** **Provide basic nutrition information, including, roles of nutrients in the body, and disorders associated with inadequate nutrition.** **What Is Nutrition?** **The process by which the body takes in and uses food.** - **The body's handling of nutrients to maintain health** - **Nutrients (some of which provide energy for processes in the body) are substances that can promote:** - - - **Nutritional Goals** - **[Quality] intake of food allows the body to function at best and promotes health.** **Quality intake should provide adequate levels of each nutrient.** - **[Quantity] intake of food promotes a healthy body weight.** **What is a Nutrient** **A nutrient is a chemical substance in food that helps maintain the body. Some provide energy. All help build cells and tissues, regulate bodily processes such as breathing. No single food supplies all the nutrients the body needs to function.** - **Good nutrition : " maintaining a nutritional status that enables us to grow well and enjoy good health"** - **NUTRITIONAL STATUS :** **condition of health as it relates to food and nutrient intake, absorption and utilization** **It deals with all the processes involved in the intake and the utilization of the proper amounts of nutrients to maintain health** **Public Health Nutrition** **Why Nutrition** **Nutrition is also very important during certain periods of life ♣ Infancy ♣ Till 5 years of age ♣ Adolescence ♣ Pregnancy and lactation** **General Nutrition Concepts** - **Influences of Nutrition** - **Health \-\-- Appearance** - **Behavior \-\-- Mood** **Role of Nutrients in Diet** - **Growth and development Provide energy** - **Regulate metabolism** **Variables which affect the need for nutrients:**  **[Diet:- ]** **a mixture of foodstuffs, which are selected to satisfy the daily nutritional requirements of the body.... The foods one consumes: The quality of which affects the risk of chronic diseases** **Diet produces energy** **What you eat is the fuel that allows your muscles to move**  - **Dietetics: the practical application of principles of nutrition: includes the planning of meals for the well and the sick.** **[Adequate nutrition is characterized by:]** **1-Daily intake of nutrients, which are (quantitatively and qualitatively).** **2-Adequate nutrition should consider physiological status and pathological disorders.** 1. **Normal digestion, absorption, metabolism, excretion.** FOOD ---- **Is a composite mixture of various nutrients in a varying proportion, together with water** **What does food do for me?** - **Provides energy** - **Repairs injured tissue** - **Helps our bodies grow** - **Contributes to good general health** **[Eat Variety of food types]** **A balanced diet means not eating too much of one thing. You spread your daily food intake across different food sources to allow a good a balance of different nutrients** **This gives your body all the nutrients it needs to perform different tasks** - **What is a balanced diet?** **Imagine everything you eat divided into 3 equal groups** - **One third should be carbohydrates** - **One third should be fruit and vegetables** - **One third should be proteins, dairy, fats and sugars combined** - **Sugars and fats should be a very small proportion of a balanced diet** **How many calories do you need?**   **Acceptable macronutrient distribution range (AMDR):** **A range of intake for a particular macronutrient (carbohydrates, fat, protein) that provides adequate amounts of essential nutrients and reduces risk of health problems.** **AMDR For adults** **45-65% of the total calories from CHO** **20-35%of the total calories from Fat** **10-35%of the total calories from Protein** **Total Caloric Intake** **\* Example :** **If total calories allowed = 1500 cal.:-** **Then CHO content = 1500 X 60% = 900 cal.** **CHO Content (quantity and quality)** **Complex CHO = 70 % x 900 = 630 cal ≈ 160 gm** **Sugars \< 10 % x 900 = 90 cal ≈ 22 gm** **Complex CHO : with low G / l :** **grains-legumes-pasta-whole grain bread-boiled rice** **Simple CHO : refined sugars , fruit sugars** **Fat Content** **\* Total fat content : \> 30% of total calories** **\* Essential fatty acid supplements ( soya beans, nuts, rapeseed oils)** **\* Omega 3 fat ( fish) anti atherogenic ( 2.3 fish meals/wk or fish oil caps 0.3 g)** **Protein** \* **Average total protein content: 15% of total calories( 12-20%) in total 2000 kcals** **15%= 300 cal.= 75 gm prot., \* Or ( 0.8-1.2 gm/kg body weight)** **An Example in Diet Construction:** **1- if a Pt needs daily requirement = 2500 calories** **2- and is overweight ( BMI = 35 )** ∴ **Goal : to lower body weight by 1kg/ wk** **( 1 kg loss requires loss of 7000 calories (1000 /day X 7 )** **3-** ∴ **subtract from his intake 1000 calories / day** **4-** ∴ **daily intake : 2500 -1000 = 1500 calories** **To distribute the 1500 calories :- e.g.** **60% CHO + 24 % fat + 16 % protein = 100 %** **(900 cal.) (360 cal.) (240 cal.)** **↓ ↓ ↓** **( 225 gm ) ( 40 gm ) ( 60 gm )** **CHO fat protein** **How to Calculate BMR** **1. Convert body weight kilograms** **Weight in Pounds 2.2** **2. Females - Multiply step \#1 by 0.9** **Males - Multiply step \#1 by 1.0** **3. Multiply step \#2 by 24 to get basic kcals needed/day** **Example** **Jessie weighs 125 lbs. What is her BMR?** **1. Convert body weight kilograms** **Weight in Pounds 2.2** **2**. **Females - Multiply step \#1 by 0.9** **56.82 x 0.9 = 51.14** **3. Multiply step \#2 by 24** **51.14 x 24 = 1227.3 kcals/day (BMR)** **Ex: Henry's BMR is 1575. He ran for 1 hour on the treadmill. Each minute he burned 10 Calories. What is his new calorie requirement?** **10 Calories x 60 minutes = 600 Calories** **1575 + 600 = 217** **Problem \#1** **Jared and Sandy danced fast for 15 minutes. For each minute danced, they each burned 4** **calories. Jared's BMR is 1775 and Sandy's is 1552. What are their TOTAL calorie** **requirements?** **4 calories x 15 minutes = 60 calories** **Jared = 1775 + 60 = 1835 calories** **Sandy = 1552 + 60 = 1612 calories** **1835 + 1612 = 3447 calories together** **Problem \#2** **Bethany weighs 112 pounds. Most days she requires a 25% increase in calories over her typical needs. What is her new calorie requirement?** **BMR = 112/2.2 = 50.9** **50.9 x 0.9 = 45.81** **45.81 x 24 = 1099.4** **1099.4 x.25 = 274.86** **1099.4 + 274.86 = 1374.26 calories** **Student activity** **Activity 1** **You are conducting a clinical nutrition evaluation for a 20-yr-old woman, 165 cm tall, weighing 50 Kg, and engaged in light to moderate activity.** **1.What are the components of the daily total energy expenditures (TEE)?** **2.If the Resting Energy Expenditure (REE) for this lady is 1,300 kcal/day. What would be her estimated daily total energy expenditure (TEE)?** **3.How would this total amount be divided between different components of TEE?** **4.Calculate** **the daily caloric needs for this lady** **Energy content of food** **The energy content of food is calculated from the heat released from total combustion and oxidation of one gram of this substance in calorimeter.** **It is expressed in kilocalories ( Cal or Kcal).** **Calorie is the unit to measure energy content of food** **Activity 2** ** For an adult male of 70 kg weight, if the daily average energy requirement recommended for him is 1800-2,000 Cal/day, comment on the suitability of the following diet from a nutritional point of view taking into account the AMDR. and the Caloric content of nutrients\*\*.**