We led a study to find out how genes have such a significant influence on why humans (and dogs) become overweight. It was their reputation for greediness that led us to focus on labrador retrievers. Genes are responsible for 40%-70% of human obesity – the rest is related to life experience.

The gene found to be most strongly associated with obesity in Labradors is called DENND1B. Humans also carry the DENND1B gene, and the researchers found that this gene is also linked with obesity in people.

Researchers found that changes in a particular gene, one of the building blocks of biological code that produces the blueprint for how our bodies work, alters the chemical signals that tell our brains we've had enough to eat.