4719.0 - Overweight and Obesity in Adults, Australia, 2004-05 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 25/01/2008  First Issue
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CHAPTER 4. LIFESTYLE RISK FACTORS


INTRODUCTION

Behavioural or lifestyle risk factors increase the risk of ill health, but unlike other factors such as age, sex, and genetics, lifestyle behaviours can be altered. Regular exercise and diet are factors in preventing obesity, diabetes and some mental health problems. Conversely, smoking, excessive alcohol consumption and obesity are major risks for a range of chronic diseases including mental health problems.


In the NHS, adult respondents are asked to report on lifestyle risk factors such as current daily smoking, alcohol consumption at a risky to high risk level, insufficient physical activity (sedentary or exercise at a low level), and inadequate fruit or vegetable intake (less than 2 serves and 5 serves respectively per day). The consumption of skim or reduced fat milk was also collected for use as a proxy for fat intake.


It should be noted that these measures are broad concepts based on recall rather than detailed data collected from observation or diary techniques. There may also be an awareness on the part of respondents about the social desirability of their responses. While the personal interview methodology used in the NHS may result in a greater likelihood of behaviours which are obvious to interviewers being reported, the level of the activity reported, for example, may be affected by respondent concern about the acceptability of their responses.



OVERVIEW

In 2004-05, the pattern of reporting these risk factors was similar among adults classified as overweight or obese, and those classified as normal weight or underweight. Almost all adults reported at least one of the four key lifestyle risk factors (97%).


The two most frequently reported lifestyle risk factors among adults were inadequate fruit or vegetable intake (90%) and sedentary or low level exercise (70%), and the most common pattern was to report them both, without also reporting smoking or drinking at risky levels (44%). In comparison to those classified as normal or underweight, adults who were overweight or obese were slightly more likely to report in this way (43% and 44%).


Among females, there was a difference in responses between those classified as overweight or obese, and other females. The former group were more likely to report sedentary or a low level exercise alongside inadequate fruit or vegetable intake (49% compared to 46%), and less likely to report inadequate fruit or vegetable intake alone (14% compared to 18%). The other response patterns were similar in both the overweight or obese, and normal or underweight groups.


Most adults reported both of the two common lifestyle risk factors (sedentary or a low level exercise and inadequate fruit or vegetable intake), making two lifestyle risk factors the most common outcome (52%).

4.1 LIFESTYLE RISK FACTORS(a)

Men
Women
All adults
%
%
%

Underweight or normal(b)(c)

Number of risk factors
One risk factor
25.1
24.5
24.7
Two risk factors
47.1
53.3
50.7
Three risk factors
19.6
15.7
17.4
Four risk factors
4.6
3.1
3.7
Selected risk factors
Nutrition only
20.7
17.9
19.1
Nutrition and exercise
37.9
45.8
42.5
Nutrition, smoking and exercise
14.5
10.3
12.0
Total with risk factors
96.4
96.6
96.5
No risk factor
3.6
3.4
3.5
Total
100.0
100.0
100.0
Total ('000)
2 653.5
3 741.2
6 394.6

Overweight or obese(b)(c)

Number of risk factors
One risk factor
25.5
22.2
24.2
Two risk factors
48.0
56.2
51.4
Three risk factors
20.6
16.0
18.7
Four risk factors
3.4
2.1
2.9
Selected risk factors
Nutrition only
21.3
14.4
18.4
Nutrition and exercise
39.4
49.4
43.6
Nutrition, smoking and exercise
12.2
10.9
11.6
Total with risk factors
97.5
96.5
97.1
No risk factor
2.5
3.5
2.9
Total
100.0
100.0
100.0
Total ('000)
4 310.9
3 055.1
7 366.0

(a) Lifestyle risk factors. See Glossary.
(b) BMI. See Glossary.
(c) Excludes those for whom BMI category was not known.
National Health Survey 2004-05


Looking at NHS data over the period since 1989-90, and adjusting for changes in the age structure over the period, changes in the proportion of overweight or obese adults reporting certain lifestyle risk factors are consistent with a broader change amongst the total adult population. Rates of smoking decreased among adults who were overweight or obese (from 26% in 1989-90 to 23% in 2004-05), however this reflected a general decrease in smoking rates across the whole population (for example among normal weight, 29% in 1989-90 to 24% in 2004-05). Similarly, rates of risky or high risk drinking among the overweight or obese increased from 1995 onwards (from 8% in 1995 to 14% in 2004-05) but they also increased in people who were classified as having normal weight (from 8% to 13%). The proportion of overweight or obese people who had a low or sedentary exercise level did not change substantially over time, nor did the rates of sedentary and low exercise among people with a normal BMI (table 4.8), similar to the total adult population.



EXERCISE

The NHS measures current levels of physical activity by asking respondents to report on all exercise for sport, recreation or leisure undertaken in the two weeks prior to the survey interview. The NHS also collected information on frequency, duration and intensity (walking, moderate or vigorous) of the physical activity, with each person classified to an exercise level of sedentary, low, moderate or high.


In the NHS, people are asked how much they did of three different types of exercise - vigorous exercise, moderate exercise and walking for sport, recreation or fitness. In 2004-05, overweight or obese adults were less likely to report vigorous exercise and more likely to report walking as their only form of exercise, compared to other adults. Of the overweight or obese adults classified as having a moderate or high level of exercise, 36% reported doing vigorous exercise in the two weeks prior to interview, compared to 43% of underweight or normal weight adults classified at similar exercise levels. One-fifth (20%) of overweight or obese people with a moderate or high exercise level reported walking as their only form of exercise, compared to 17% of those who were underweight or normal weight.


In general, reported exercise levels were similar across BMI categories. Overweight or obese adults were slightly less likely to exercise at a moderate to high level (29%) than those underweight or normal weight (32%).


Men who were classified as overweight or obese were slightly more likely to be sedentary or have exercised at low levels (67%) than men in the underweight or normal weight range (65%). This difference was greatest in the 18-24 years age group (60% of underweight or normal weight adults compared to 50% of overweight or obese adults in the same age group).

4.2 Sedentary-low exercise, Men
Graph: 4.2 Sedentary-low exercise, Men


4.3 Sedentary-low exercise, Women
Graph: 4.3 Sedentary-low exercise, Women



Of overweight or obese women, 76% were sedentary or exercised at low levels, more than women who were not overweight (70%). For overweight or obese women, this lifestyle risk factor was lowest among 18-24 year olds (66%) and increased in the older age groups. In contrast, for women in the underweight or normal weight range, sedentary and low exercise levels were lowest among 55-64 year olds (62%), and the difference between the two groups of women in terms of the proportion with this lifestyle risk factor was also greatest in this age group (62% compared to 74%).


A perception of being overweight was related to a tendency to exercise less. Of all adults aged 18 years and over who considered themselves to be overweight, just over one-quarter (26%) engaged in moderate to high levels of exercise, compared with 33% of adults who thought they were underweight or acceptable weight. Of adults who were overweight or obese and considered themselves to be overweight, 26% exercised at moderate to high levels, compared with 34% of overweight or obese who thought they were underweight or acceptable weight. This pattern was the same for adults who had an underweight or normal weight BMI (table 4.8).



DIETARY BEHAVIOUR

FRUIT OR VEGETABLES

A majority of adults (90%) did not consume the recommended amount of fruit (2 or more serves) or vegetables (5 or more serves). This proportion was similar regardless of body weight (refer to Glossary for recommended intake of fruit or vegetables).


Age is related to fruit or vegetable intake. Older adults are more likely to consume an adequate amount of fruit or vegetables compared to young adults. Adults aged 55-64 years were the most likely to consume inadequate fruit or vegetables (85%) compared to 95% of the 18-24 years age group.



SKIM OR REDUCED FAT MILK

Adults' diets should be low in fat, especially saturated fat, because it is more easily deposited as fat tissue than unsaturated fat (Better Health Channel 2006). Although milk is a good source of protein and calcium, it does contain saturated fat. Reduced fat or skim milk provides a healthier alternative, contributing to a healthy diet.


Approximately 50% of people who were overweight or obese reported consuming skim or reduced fat milk, compared to 41% of people who were underweight or had normal weight. Overall, women (52%) were more likely than men (40%) to consume skim or reduced fat milk, however both males and females were more likely to use skim or reduced fat if they were overweight or obese. Skim or reduced fat milk was used by 59% of overweight or obese women (compared to 47% of underweight or normal weight women) and 44% of overweight or obese men (compared to 33% underweight or normal weight men).


Consumption of skim or reduced fat milk generally increased with age, however in all age groups, skim or reduced fat milk use was higher in overweight or obese people. The greatest difference in the consumption of skim or reduced fat milk between overweight or obese and underweight or normal weight men and women was in the 55-64 years and 45-54 years age group. Almost two-third (66%) of overweight or obese women aged 45-54 years reported using skim or reduced fat milk, compared to 50% of women in the same age group who were underweight or had normal weight. Just over half (53%) of overweight or obese men aged 55-64 years used skim or reduced fat milk, compared to 38% of men in the underweight or normal weight range.

4.4 Skim or reduced fat milk consumption
Graph: 4.4 Skim or reduced fat milk consumption



Whether people perceived they were overweight was related to whether they reported usually consuming skim or reduced fat milk. Of all adults who thought they were overweight, 54% used skim or reduced fat milk, compared to 42% of people who thought their weight was underweight or acceptable weight. Of all adults who were classified as overweight or obese and also considered themselves to be overweight, 54% used skim or reduced fat milk, but this dropped to 45% for those who were overweight or obese and thought that their weight was underweight or acceptable weight. This pattern was repeated in both men and women, with the most pronounced difference among men aged 18 to 24 years. In this age group, skim or reduced fat milk was used by only 28% of overweight men who believed they were underweight or acceptable weight, increasing to 47% among those who thought they were overweight.

4.5 Consumption of skim or reduced fat milk
Graph: 4.5 Consumption of skim or reduced fat milk




SMOKING

Overall, people who were overweight or obese were no more likely to be daily smokers than those who were underweight or normal weight (20% and 22% respectively). However, younger people who were overweight or obese were more likely to report daily smoking than their non-overweight counterparts.


Almost one third (30%) of overweight or obese adults aged 18-24 years were daily smokers, compared to less than one quarter (24%) of underweight or normal weight 18-24 year olds. In the age group 35-44 years proportions of smoking were similar across BMI categories. However from age 45 onwards the pattern reversed, with proportion of smoking among overweight or obese adults lower than underweight or normal weight people. Some 14% of overweight or obese persons aged 45 years and over were daily smokers, compared to 18% of underweight or normal weight people.


This pattern was apparent in both male and female smokers, however it was most apparent in men. Of overweight or obese men aged 45 years and over 15% were daily smokers, lower than the proportion of those who were underweight or normal weight (22%). The proportion of smokers among overweight or obese women aged 45 years and over was 12%, similar to those who were underweight or normal weight (15%).


Many studies have reported links between the cessation of smoking and the likelihood of being overweight (Lahti-Koski et al. 2002). In the 2004-05 NHS, male ex-smokers were more likely to be overweight or obese (67%) than men who had never smoked (60%) or who currently smoke (57%). In almost all age groups a high proportion of male ex-smokers were overweight or obese compared to current smokers and those who had never smoked. The proportion of male ex-smokers who were overweight or obese was highest at 55-64 years (77%), while among current smokers the age group with the highest proportion was the 35-44 year age group at 64%. Female ex-smokers were also more likely to be overweight or obese (50%) than current smokers (44%) and women who had never smoked (43%). However for age groups less than 35-44 years, proportions of people who were overweight or obese were similar among ex-smokers and current smokers. The proportion of overweight female ex-smokers was highest in the age group 55-64 years at 62% (table 4.8).

4.6 Overweight or obesity (a)(b), Men
Graph: 4.6 Overweight or obesity (a)(b), Men


4.7 Overweight or obesity (a)(b), Women
Graph: 4.7 Overweight or obesity (a)(b), Women




ALCOHOL CONSUMPTION

In the NHS data was collected about alcohol consumed in the week prior to interview. This is used to calculate levels of long term risk from alcohol consumption. For definitions of alcohol risk levels see the Glossary in this publication.


The proportion of people who were overweight or obese who drank at risky or high risk levels (14%) was similar to those in the underweight or normal weight range (13%). Women classified as overweight or obese were less likely to drink at risky or high risk levels (11%) compared to females classified as underweight or normal weight (13%). Among men, rates of risky or high risk drinking were largely the same across the BMI categories.


Overall, men who drank at risky or high risk levels had similar rates of overweight or obesity (66%) compared to men who drank at low risk levels (62%). However the proportion of these men who were overweight or obese was higher than the proportion for men who had never consumed alcohol or had last consumed alcohol more than one week ago (59%). In the younger age groups, men who drank at risky or high risk levels were more likely to be overweight or obese, however this difference was less marked in the older age groups. Among women, overweight or obesity was less common in risky or high risk drinkers (40%) and low risk drinkers (43%) than among women who had never consumed alcohol or last consumed alcohol more than one week ago (48%). This pattern was strongest in the older age groups (table 4.8).