Exam Questions

List the features of a good study

• Clear aim

• Representative sample

• Large sample size

• Valid & reliable results

• Were all relevant variables considered & controlled?

Describe how data might provide evidence for links between risk factors & illness & mortality

• Look for a general correlation

• In tables look for coinciding patterns

• Focus on trends not individual data points

• This may involve comparing 1 set of data from control groups to other groups.

• If error bars are present, non-overlapping error bars means there’s more chance of a significant relationship

• Look out for details of the study

• Data manipulations may be required e.g. calculating percentage increases to support your conclusions.

Describe how data linking risk factors to illness/mortality may be critiqued?

• Correlation doesn’t confirm causation

• Have other risk factors been ruled out/ controlled for?

• Are there parts of the graph/data that don’t fit the trend?

• Are the error bars overlapping in the region of correlation?

• Is there anything in the design of the study not controlled? E.g. sample size, unrepresentative sample

• Could there be bias?

Explain the concepts of energy intake and expidenture

• Energy is gained in the form of dietary carbs, fat & protein

• When these molecules are digested, absorbed & assimilated, their stored chemical energy is added to the body

• These stored molecules are broken down in processes such as respiration, where there energy is used e.g. muscle contraction

• Energy expenditure is connected to BMR

Explain how energy imbalances are related to weight gain or loss

• When energy gain = energy used there is no net weight gain/loss

• When more energy is consumed than used there is weight gain

• When more energy is used than gained there is weight loss

• Excessive weight gain can lead to obesity