Looked around and found some statistics:
http://www.wrongdiagnosis.com/o/overweight/stats.htm
* Overweight prevalence statistics for men in the USA:
o 58% of men aged 20-34 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 67.6% of men aged 35-44 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 71.3% of men aged 45-54 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 72.5% of men aged 55-64 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 77.2% of men aged 65-74 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 66.4% of men aged over 75 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
* Overweight prevalence statistics for women in the USA:
o 51.5% of women aged 20-34 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 63.6% of women aged 35-44 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 64.7% of women aged 45-54 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 73.1% of women aged 55-64 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 70.1% of women aged 65-74 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
o 59.6% of women aged over 75 are overweight in the US 1999-2000 (Health United States, 2003, NCHS)
* 50% of women aged 20 to 74 are overweight or obese in the US (The National Women?fs Health Information Center)
* 12% of adolescents aged 12 to 17 overweight in the USA (US Government Statistics)
* 6% of adolescents aged 12 to 17 overweight in the USA 1976-80 (US Government Statistics)
* 9% increase in adults overweight in the USA 1976-80 (US Government Statistics)
* 14% of children aged 6 to 11 overweight in the USA 1988-94 (US Government Statistics)
* 9% increase in adults overweight in the USA 1976-80 (US Government Statistics)
* Estimated 22 million children under 5 years are overweight worldwide(World Heart Federation Fact-Sheet, 2002)
* 1 in 4 children are overweight in the USA (World Heart Federation Fact-Sheet, 2002)
* 14% of women overweight in Canada 1996/97 (Statistics Canada, National Population Health Survey, Health Canada, 1996/97)
* 25% of men overweight in Canada 1996/97 (Statistics Canada, National Population Health Survey, Health Canada, 1996/97)
* 517 women per 1,000 population were overweight or obese in Australia 1999-2000 (Australia?fs Health 2004, AIHW)
* 673 men per 1,000 population were overweight or obese in Australia 1999-2000 (Australia?fs Health 2004, AIHW)
* 298 women per 1,000 population were overweight in Australia 1999-2000 (Australia?fs Health 2004, AIHW)
* 482 men per 1,000 population were overweight in Australia 1999-2000 (Australia?fs Health 2004, AIHW)
* 51.9% of female population are overweight in Australia 1999-2001 (Australia?fs Health 2004, AIHW)
* 67.4% of male population are overweight in Australia 1999-2001 (Australia?fs Health 2004, AIHW)
* 18% of population in China (WHO World Health Report, 2003)
Costs for Overweight: Total cost: $99.2 billion