By restricting the amount of a certain amino acid, methionine, in dogs’ diets, pet food formulators with Slim Health Pet Food developed a product that may help dogs lose weight without changing their routine or restricting calories. Subsequently, the dog food may extend the dogs’ lives by reducing obesity related diseases, said Vince Marsland, chief executive officer of Slim Health Pet Food.

“There is a very clear connection between obesity and longevity,” he said. “Morbid obesity has secondary effects and with those also come reductions in pets’ lifespans.”

Slim Health’s legal team is well aware that claims about extending pets’ lives have led other companies into legal troubles, Marsland said. However, unlike in that case, Slim Health isn’t claiming to add a certain number of years to a pets’ life. Likewise, empirical evidence backs up the claim that losing weight helps pets live longer, just like people.

How methionine restriction pet food works

Two scientists, Drs. Frank Greenway and Thomas Gettys, developed the methionine-restriction dog diet for Slim Health Pet Food. They observed a metabolic pathway in dogs and other mammals that could be manipulated to help weight loss.

When the scientists restricted the amount of the amino acid methionine in a dog’s diet, that dog’s liver sensed the low levels of the amino acid. In response, the liver released the hormone FGF21. That hormone increases energy expenditure, lowers fat deposition, decreases circulating and hepatic lipids, and increases insulin sensitivity, according to Slim Health Pet Food’s informational materials. Those effects resulted in weight loss.

Slim Health Pet Food’s products are still undergoing testing. The dog food may be on the market in six months, once a final feeding trial is completed. Methionine restricted cat food will take longer, while palatability is studied in obese cats.

“Conducting feeding trials in a humane way was really important to us,” said Marsland.

Dogs in the test groups ate a high fat dog food for four months to plump up, then were transitioned over two months to the methionine restricted weight loss diet.