Module 3: Energy Balance and Weight Management for Athletes Flashcards
Define energy balance
The mathematical relationship between energy intake and energy expenditure
- Energy balance = energy intake - energy expenditure
What is energy intake?
- Sum of the calories (food energy) that an individual takes in per day
- It describes the quantity of calories but does not address the behaviors that underpin energy intake
Define energy expenditure
- Energy expenditure describes the quantity of calories (food energy) used by the body per day
- Multi-factorial and influenced by a variety of things (mor complex)
When will there be a weight loss and weight gain?
- Weight loss: EE>EI (negative energy balance)
- Weight gain: EI>EE (positive energy balance)
What is energy intake influenced by?
- Influenced by multiple social and behavioral factors
- In a condition of food security, humans eat rather than feed
- Humans should just eat when hungry and stop when full in theory
- Factors influence the amounts and types of foods people eat or their eating pattern such as mental health issues, hormonal drivers to eat, social eating (birthdays, social events)
Teaching people what to do does not always mean….
That they will do it! There are things they enjoy that they don’t want to give up
What are the components of energy expenditure?
TEE = REE + NREE
What comprises REE?
- BMR/RMR = Basal or Resting Metabolic Rate
- Although BMR and RMR slighly differ from each other, RMR should be an accurate estimate of your BMR
What comprises NREE?
- NEAT = Non-exercise activity thermogenesis
- TEF = Thermic effect of food (influence on body weight is often overstated)
- EAT = exercise activity thermogenesis
What makes up the largest portion of EE?
- REE makes up majority, EAT makes up very little
- Can upregulate BMR
- NEAT is decreasing with obesogenic environment, conveniences, sitting
- Blue zones: higher NEAT than other areas
What is RMR influenced by?
- RMR is influenced by a wide-variet of factors including body composition and intensity and duration of planned physical activity
- RMR increases with FFM therefore strength training important
What is energy intake and energy expenditure influenced by?
Why do sports dietitians estimate TDEE?
- Establish a standard for energy intake adequacy
- Assess nutritional status
What is used to estimate TDEE?
- Predictive equations
- ONLY an ESTIMATE of an athlete’s energy requirements
- The reliability of the estimate is only as good as the information available to the dietitian
What do predictive equations use?
- Use weight, height, FFM and/or age to estimate RMR
- Research shows most predictive equations tend to underestimate RMR in athletes
- The dietitian will choose the equation they prefer to use and defend
Name predictive equations commonly used. Which have the strongest correlations?
- Owen
- Harris-Benedict
- Mifflin
- Cunningham
- EER
- Harris-Benedict and Cunningham have the strongest correlations. (Cunningham seems to be the best for female and male athletes)
What does the HBE consider?
- Height, weight, age, and gender
- Only an estimate of RMR! Still need to multiply by activity factor for athletes, this is where it gets complicated
What is the conversion of lbs to kg and inches to centimetres?
- 1 lb = 0.454kg
- 1 inch = 2.54 cm
What does mifflin-st Jeor equation consider?
Considers height, weight, age, and gender
When should you round when calculating RMR?
- Rounding is done to the final calculated value ONLY
- Serial rounding detracts from the estimate
- Standard rounding conventions are used (38→40; 33→30)
- If a range is offered it is given as a span of either 50 or 100 (1762.18 → 1750-1800 or 1750-1850)
What is an activity factor and what is the factor for sleeping/sitting/lght activity/light training/heavy training?
- A value that is applied ON TOP of RMR to account for NEAT and EAT
- To accurately estimate the contribution of both NEAT and EAT to the athlete’s TDEE, we collect information on the athlete’s activity levels across their entire day
Once you have calculated the AF of an athlete what do you do?
- Divide the total amount by 24 hrs to get the AF
- Multiply the RMR by the activity factor to get their TDEE
Michael Phelps estimated energy intake is 12,000kcal/day. Why is it so high?
- Energy requirements in elite athletes can be very high
- Would have a high RMR due to size and amount of FFM
- Engaging in high intensity, would have a large AF
- EE would be extremely high thus justifying need for energy intake to be extremely high
What are the estimated energy requirements by sport?