DRAFT Australian Dietary Guidelines - Eat For Health

Compared to having a BMI between 18.5 and 25, at a BMI of 30–35kg/m 2 , median survival is
reduced by 2–4 years, at BMI 40–45kg/m 2 it is reduced by 8–10 years [706]. The relative increase
in mortality rate attributable to obesity tends to decline with age [715]. Mortality and morbidity
are also associated with the amount of weight gained in adult life [89, 685, 688].
Many obesity-related conditions are preventable, and several are at least partially reversible
through weight loss achieved by adopting a nutritious dietary pattern and active lifestyle [89, 685,
688].
While the greatest risk to health on a population basis is associated with being overweight, being
underweight can also have adverse health consequences including decreased immunity (leading to
increased susceptibility to some infectious diseases), osteoporosis, decreased muscle strength, and
hypothermia[37]. Among older people, being underweight may be more deleterious to health than
being overweight [716].
4.1.2.2 Children and adolescents
The most immediate consequences of overweight/obesity in childhood is social discrimination
associated with poor self-esteem and depression, increased risk of development of negative body
image issues, and eating disorders [688]. Overweight children and adolescents are more likely to
develop sleep apnoea, heat intolerance, breathlessness on exertion and reduced exercise
tolerance, tiredness, some orthopaedic and gastrointestinal problems, steatohepatitis and early
signs of metabolic and clinical consequences, such as hypertension, hyperinsulinaemia,
hypertriglyceridaemia and type 2 diabetes [688, 717].
A major long-term consequence is that overweight children are more likely to become overweight
adults with an increased risk of chronic diseases and early mortality [688, 717-719]. The risk of
chronic disease is increased with rapid weight gain in infancy and early childhood [88, 89].
In infancy and early childhood, underweight and failure to thrive can be more prevalent than
overweight and obesity in some communities. Failure to thrive is most commonly a result of
socioeconomic factors, including poor living conditions [720] but can also occur among affluent
sections of the community due to inappropriate dietary restrictions, for example based on fears
about ‘unhealthy’ dietary habits leading to the development of atherosclerosis [721]. Specialist
advice should be sought on underweight and failure to thrive in infants and children.
Inappropriate dietary restriction and eating disorders occur in some adolescents [722].
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