Respiratory Quotient, its clinical importance and Balanced Diet

Energy requirement of a normal person While calculating we should consider the energy required for Maintenance of BMR Thermogenic effect of food (SDA) Extra energy expenditure for PA

SDA Values Carbohydrates 05% Protiens 30% Fats 15% Mixed Diet 10%

Physical Activity Level (PAL) Energy required in kcal/hour (over and above BMR) 1. Eating 28 2. Writing 30 3. Driving a car 63 4. Typing at high speed 100 5. Walking 140 6. Cycling 175 7. Running 490 8. Swimming 550

Energy Requirement and Occupation Type of activity Occupation Light Office workers, lawyers, accountants, doctors, teachers, architects, shopworkers Moderate Students, industry workers, farm workers, housewives without mechanical appliances Very active Agricultural workers, miners, unskilled laborers, athletes, factory workers Heavy work Lumber jacks, blacksmiths, and construction workers

Additional Calories to be added for each category to their normal BMR Sedentary Work BMR+30 % Moderate Work BMR+40 % Heavy Work BMR +50% Very Heavy Work BMR+70 %

Calculation for energy requirement for a 55 kg person doing moderate work For BMR = 24 x 55 kg = 1320 kcal + For activity = 40% of BMR = 528 kcal Subtotal = 1320 + 528 = 1848 kcal + Need for SDA = 1848 x 10% = 185 kcal Total = 1848 + 185 = 2033 kcal Round to nearest multiple of 50 = 2050 kcal

Proximate Principles Carbohydrates Fat Proteins Minerals Vitamins Additional requirements for growth pregnancy lactation and convalescence are to be provided in the food.

Respiratory Quotient When food is oxidized, whether in an open system or closed biological system, oxygen is consumed and CO2 produced. Volume of CO2 produced Volume of O2 consumed = RQ Ratio in steady state / Unit time

Carbohydrates are completely oxidized and the volume of O2 used is equal to CO2 produced C6H12O6 + 6O2  6CO2 + 6H2O RQ = 6CO2 6O2 = 1

Fats C57H104O6 + 80 O2  57 CO2 + 52 H2O RQ = 57 = 0.71 80 Other fats have RQ  0.70

Using specialized technique the RQ is found to be 0.82 Proteins RQ of proteins is a little complex to determine as it contain N & S in addition to C, H, O. Using specialized technique the RQ is found to be 0.82

Alcohol C2O5OH + 3O2  2CO2 + 3H2O RQ = 2/3 = 0.67

Human Use normally mix type of food RQ of an intact person naturally will be the sum of RQ of all the three major type of food. Carbohydrates Fats Proteins

Ordinary mixed diet RQ = 0.85 Postabsorptive State No food being consumed in preceding 12 – 14 hours RQ = 0.82

When diet is rich in Carbohydrates the RQ will be more close to one i When diet is rich in Carbohydrates the RQ will be more close to one i.e. High More fats = Lower RQ

Methods for determination of RQ of Man Two method Open Circuit Closed Circuit

Open Circuit Made to breath in a specially designed bag called Douglas Bag for few minutes Volume of Breathed air is measured in a gasometer Subjected to gas analyzer Where CO2 is absorbed by KOH Original volume of gas is reduced

Open Circuit Concentration of CO2 is calculated Remaining gas is allowed to react with alkaline pyrogalate which absorb O2 O2 in the expired is found out RQ is calculated volume of CO2 volume of O2

Remember that when rate of utilization of fat increases in relation to carbohydrates, RQ falls. Commonly seen in Diabetes mellitus Utilization of carbohydrates increases RQ

BALANCED DIET

BALANCED DIET Diet which provides all the five basic nutrients in a quantity which ensures healthy life is known as Balanced diet. These are : Carbohydrates Fats Proteins Vitamins and Minerals

The Food Pyramid

The Food Pyramid

Nutrient Pool

Water Water of course is another important essential nutrient required for normal metabolism of all the essential five.

Water Solvent in which the chemistry of life occurs Cell chemistry occurs in an aqueous medium Water carries essential nutrients to cells Water carries metabolic wastes away from cells Hydrolysis & dehydration reaction Stabilizes body temp

High-Sugar Diets Calories adding to excess Obesity Dental caries