A volunteer sorts collection bins of donated food at a food bank in Seattle during the early days of economic gloom in November 2008. (Elaine Thompson/Associated Press)

The figurative belt tightening people are doing when it comes to their finances during the credit crunch might cause a literal belt loosening around the waist line, a German study on indebtedness and obesity suggests.

Researchers found 25 per cent of 949 study participants who were in debt were medically obese compared to 11 per cent of the other 8,318 study participants who weren't.

"Over-indebtedness was associated with an increased prevalence of overweight and obesity that was not explained by traditional definitions of socioeconomic status," Eva Münster, from the University of Mainz, Germany, and her colleagues concluded in Friday's online issue of the journal BMC Public Health, .

The credit crunch will have health implications, Münster said.

While certain levels of income, education and occupational status are known to be linked to overweight and obesity, levels of debt are usually not considered in terms of their impact on health, a gap the researchers set out to try to fill.

The study's authors defined over-indebtedness as "lack of possible debt redemption in due time due to the relation of income and cost of living after a remarkable cutback in standard of living."

Sweet, fatty snacks cheaper

Debt can affect risk factors for chronic disease by, for example, limiting leisure time activities and the ability to attend social events, the researchers said.

They speculated those in debt may pack on pounds since their ability to choose nutritious foods is limited by their stretched pocketbook.

"Energy-dense foods such as sweets or fatty snacks are often less expensive compared to food with lower energy density such as fruit or vegetables," Münster said in a news release.

Over-indebtedness was associated with a 1.97 times higher odds for being overweight and 2.56 times higher odds for obesity, after adjusting for age, sex, education, income and health factors such as depression and smoking.

Lowering prices to increase the availability of healthy foods could be an effective public health strategy, the researchers suggested.

Limitations of the study include self-reporting of weights; the possibility that people who were overweight had a harder time finding a job and were therefore more likely to be indebted; and a lack of detailed information on indebtedness for the larger population sample.

It's not known if study participants gained weight when they lost income because of indebtedness or if they were already carrying the excess weight before their financial woes occurred.