Lecture 12- Breakfast

Question 1

Problems with smith

Answer 1

Only an association; cannot be taken as cause and effect

Question 2

Brown et al (2013) (look over) meta-analysis

Obesity and skipping breakfast

Answer 2

Increased risk of being overweight if you missed breakfast (first study)

Question 3

Levitsky (2005)

Breakfast reduces energy consumption

Answer 3

If pps miss breakfast increase energy intake at lunch

BUT it doesn’t compensate for the energy missed at breakfast

There is actually a decrease in daily energy consumption

Question 4

Pollitt et al. (1981)

Effects of missing breakfast on cognitive performance

Answer 4

Results for matching familiar figures test:

Missing breakfast increased no. Of error only in children who had IQ below the mean of the group

Incidental recall:

Small effect

OVERALL: no effects of missing breakfast

Question 5

Glucose and cognitive function

Answer 5

Brain has a high metabolic rate

Oxidizes 120 g glucose daily, equivalent to about 20% of whole body’s daily energy expenditure

Relative constancy of blood glucose levels during a typical day

Normally healthy person has regular constant levels (healthy range)

Unlikely to be the cause of cognitive decline

Question 6

Kennedy & Scholev (2000)

Boost blood glucose and better cog. performance

Answer 6

MOST cognitively demanding task (sevens); perform better after glucose boost

Question 7

Wurtman et al. (1981)

Proposed dietary effects on brain serotonin and mood and behaviour

Answer 7

High protein meal, reduced Trp (Tryptophan) in the brain as there are competing amino acids

Question 8

Carbohydrates and mood

Answer 8

THUS after carbs there are more Trp in brain and this more serotonin is being sensitized

Also evidence in increased sleepiness

Question 9

Lieberman et al. (1986)

Effects of iso-caloric lunchtime ‘meals’ on plasma tryptophan

Answer 9

Protein

Causes decline in Trp in blood stream

Sugar/starch

Slow increases (after 1-2 hours)

Question 10

carbohydrate-craving obesity

Answer 10

Carbs relieves depressed mood

Low mood may give you the dire to eat carbohydrates

Unclear whether this is conscious or unconscious

SAD disorder

pps increased carb consumption in winter

Question 11

Tryptophan

Answer 11

The amino acid tryptophan is the basic building block of the mood altering neurotransmitter serotonin.

Question 12

Young et al. (1985)

Mood effects of tryptophan depletion

Answer 12

Low T lead to higher depression scores

Question 13

Tryptophan levels in normal life…

Answer 13

We don’t experience such extreme fluctuations in T in normal life