But if experts are to be believed, compared to just 40 years ago we're eating more healthily now - we're even exercising more than we used to. Well, some of us are. And healthcare is arguably better than it's ever been, as is awareness of how being overweight and obese can affect our bodies and wellbeing.
So what went wrong? Researchers from Montreal believe they have the answer, and it's not good news if you work in an office.
According to a study published in the journal Preventative Medicine, the fact that more of us than ever are doing nine-to-five office jobs could partly account for the current rise in obesity. Or, rather, a lack of physical activity during office hours is what's making us put on weight.
Surprisingly the researchers don't blame our dependence on cars or public transport for the obesity rise, saying more people are adopting healthy habits such as walking and cycling nowadays.
Instead it's the fact that we're stuck behind our desks for eight hours a day, often without even taking a quick stroll during lunch, they claim.
Official guidelines recommend 30 minutes of exercise a day to maintain a healthy body. But if you can't manage the full 30, it's just as effective to break it up into smaller chunks (three 10-minute bursts of activity, for instance), the experts suggest.
Is your job making you fat or unhealthy? Tell us how.