L4- Diet and Body weight Flashcards
RNI
reference nutrient intake (protein, vitamins and minerals)
EAR
estimated average requirement (used for energy intake)
LRNI
lower reference nutrition intake
intake below LRNI
is insufficient for most people
DRVs depend on
age, gender and level of physical activity
How are nutritional requirements estimated
Scientific evidence reviewed and frequency of distribution for a particular group used to determine values.
- EAR: Requirement for ~50% of group (50% will require more).
- RNI: Enough to ensure needs of 97.5% are being met. Many within the group will need less.
- LRNI: Enough for only the small number of people who have low requirements (2.5%). The majority need more.
daily energy expenditure
basal metabolic rate (BMR) + Diet-induced thermogenesis (DIT) + physical activity level (PAL)
daily energy expenditure of 70 kg man and 58 kg women
1200 kj/day
9,500 kj/day
what does the basal metabolic rate do
Maintains resting activities of the body
e. g. function of all organs
e. g. ion transport and biochemical reaction
where does the majority of basal metabolic rate energy go to
skeletal muscle (30% BMR)
factors affecting BMR
- body size
- gender
- temp
- endocrine stus
- body temp
voluntary physical exercise (VPE)
energy required depends on intensity and duration of activity. reflects demands of:
- skeletal msucle
- heart muscle
- resp muscles
VPE for sedentary person
30 kJ/Kg/day
VPE for every active person
100 kJ/Kg/day
where does most energy in British diet come from
most energy derived from CHOs
energy content in food compeoennts
highest: - fat - alcohol - protein -CHO Lowest
when energy intake = expenditure
stable body weight
energy intake < expenditure
lose weight when energy stores depletes
energy intake > expenditure
energy stores (fat_ will increase
obesity is defined as
fat accumulation in adipose tissue which impairs health
obesity is BMI above what
30
obesity occurs when
energy intake exceeds energy expenditure over a period of years
obesity is associated within increased risk of
cancer
CVD
T2D
BMI=
weight (kg)/ heigh ^2(m)
height measured
without shoes
weight measured with
minimal clothing
BMI shows good
correlation with body fat measurments
BMI is weak in predicting
body fat measurements in muscular individuals
alternative to BMI
waist/ hip ratio
greater proportion of fat in upper body e.g. abdomen associated with increased risk of
- insulin resistance
- T2D
- High NP
- hyperlipideamia
- stroke
- premature death
