NUTR 400 3.1 Energy Balance

what is energy? How do we get it? When is it relased?

• the capacity to do work 

• obtained via kcals we get from fats'/carbs/proteins/alch

• released by the chem reaction of metabolism 

Three types of energy balance?

Negative energy balance- eating less than needed

Energy balance- eating the correct amount 

Positive energy balance- earring more than needed 

what cues us to eat?

hunger- regulated in the body, biological impulse to seek energy

appetite- regulated outside the body, wanting food without being hungry. affected by food environment

ghrelin (short term systems)

• makes us hungry!

• Released by the stomach, signals the brain to be hungry

• When there are low amounts of food/energy in the stomach it signals!

(leptin) long term systems 

• adjusts food intake/energy expenditure

• maintains adequate fat stores

  • note that it’s important to have some extra energy 

• mediated by leptin! Makes the brain less hungry- suppresses hunger  

• leptin is produced in the adipose tissue

components of energy expenditure (3 parts) 

Total energy expenditure = TEE

• Basal Metabolic Rate = (BMR)  60%

• Thermic Energy Affect of Food = (TEF) 10%

• Active Energy Expenditure = (AEE) 10% 

Basal metabolic rate (BMR)

• Your metabolism!

• energy required to maintain essential function that sustain life- the cost of living

  • chem reactions, maintenance of muscle tone, organ function, active transport, etc

• Largest component of TEE (60%)

• Measured by indirect calorimetry (medgem)

Factors that affect your BMR

• #1- the amount of fat free mass you have, aka muscle 

  • The more you have the higher your BMR

• Others: Age, sex, growth, hormones, starvation, illness, pregggo, ethnicity (whites have higher BMR), caffeine sleep, smoking

Fat free mass and BMR

FFM = total body mass - fat mass

• is is your muscle

• the greater the FFM the greater the BMR

  • skeletal muscle is more active than adipose tissue (fat)

• Woman will have a lower BMR since they need more fat

• Both decline with age

• Measured by an electrical current, body comp test

Thermic Effect of Food (TEE)

• The energy needed to digest/absorb/metabolize the nutrients in food

• protein requires the most! then carbs followed by fat

• does not vary between peeps, 10% is the rule of thumb

Active Energy Expenditure (AEE)

• amount of energy expended in physical activity per day

  • includes exercise and day to day movement, contractions of skeletal muscles to move and maintain posture

• MOST VARIABLE COMPONENT OF TEE, but roughly 30%

Non-exerise activity thermogenesis (NEAT)

• The non essential movement of energy day living

• contributes to AEE

• maintains posture and spontaneous movement

Growth of adipose tissue 

• during weight gain, they increase in size and number

• once a cell is made it can never go away, just shrink!

• this makes weight loss hard

Body fat distribution 

We all store our adipose cells in different places! 

1. Gynoid- pear shape, resists weight loss, more common in woman 

2. android-  apple shape, inc risk of cardiovascular disease, since the fat is in the middle of you which disrupts ones organs

Obesity, low-grade inflammation, and chronic disease

• enlarged adipose cells produce excess hormones- they are messengers!

• This causes low grade inflammation in the body; helping to cause chronic disease!

  • such as fatty liver, heart disease, inc risk of cancer, stroke, HTN, etc…

Excess weight in the US

Obesity is on the rise!

Developing obesity

Major causes:

• Inc intake of Kcals and dec physical activity (Energy imbalance) 

Other causes:

• genetics

• individual behaviors 

• environmental factors, things like sleep that dec BMR

Body mass index (BMI) 

An indirect anthropometric measurement of body fat, based of of height and weight 

< 18.5 = underweight- risk

18.5 - 24.9 = healthy- low risk

25 - 29.9 = overweight- slight risk

30+ = obesity- risk

• LIMITATION- BMI does not consider body comp, like an athlete! 

Weight bias

Negative attitudes/beliefs/assumptions towards overweight people

• emerages prior 3 years of age

• #2 source of bias in the US- race is #1

• negative impact on fat people, medical care, health, social interactions, jobs, etc

Yo-yo dieting

bad!

• the tendency to gain weight over time, lowers metabolism, nutrient deficiencies, ED’s

Chronic dieting

• self critical/distorted body image, preoccupation with food, social isolation, weight cycling nutrient deficiency lower metabolic rate

• your BMR lowers as you do this, making it harder to loose weight after these fat diets

Fat diets

made to fail!

• temporary solutions

• money makers for companies

• not long term

• not enough nutrients/kcals, causes ED’s

Healthy weight loss

• healthy rate is 1-2lbs a week 

• life style change- physical activity, nutritious eating, sustainable behavior change 

• S M A R T goals! 

Nutritional considerations of healthy weight loss

• develop a kind relationship with food- there are no “good” or “bad” foods

• focus on moderation and portion size

• eat regularly throughout the day

• nutrient dense foods

• non-startchy veggies, whole grains, fruit, lean protein

• set small realistic SMART goals