More and more people are being classified as obese, now about 1.9 billion around the world. Our pets are also becoming more obese. Much of that is easy to understand, as people often overfeed pets and don't give them enough exercise. But obesity is rising in dogs and cats even when they don't overeat or under-exercise. What's going on? Research on pet obesity is uncovering several potential answers, like genetic links, the quality of our food, and even the use of antibiotics.
The good news is that animals could help us disentangle those environmental factors, too. Factory farm animals are traditionally fattened with antibiotics that transform their gut so they need less food to gain weight. New regulations have pushed antibiotic use in UK food-producing animals to their lowest level since data were first published and the EU has banned antibiotics as growth promoters in feed.
If antibiotics fatten animals, could they be doing the same to humans?
The answer to that question lies in your gut. The microbiome describes the genomes of the vast colonies of micro-organisms – bacteria, fungi, protozoa, viruses, all 100 trillion of them – living in your digestive system. This community influences your weight: germ-free mice that receive gut microbes from an obese (human) twin gain more weight and body fat than mice that receive microbes from the lean twin. An imbalance in the microbiome possibly leads to not only obesity, but irritable bowel syndrome, coeliac disease, and type 2 diabetes.
Read about other research findings on obesity in people and their pets at BBC Future.
(Image credit: Tripp)