article: Celebrities and dietitians have been promoting back-to-basic diets and warning us off processed foods for years - and the trend is now taking hold in the pet world. Three-and-a-half-year-old black labrador Baylie swapped sweet treats and processed dog food for a diet of free range raw meat, offal and bones in his quest to lose weight. His owners, Margaret and Patrick Evans from Leeds, say he's now 'a different dog' after losing a stone and a half in eight weeks through the doggy diet - the weight of four chihuahuas. Scroll down for video . Flab to fab: Baylie learnt where the doggy biscuit tin was and was even caught pilfering it, left, by his owners. But he's a much more lean machine, right, after starting his new weight loss programme . The plan was devised by Vicky Marshall, who runs a natural dog food company and realised that none of her 5,000 customers' dogs have weight problems. She worked out Baylie's weight and calculated special portions of carefully chosen lean meats in order for him to shed the pounds. She said: 'Dogs are carnivores - they have evolved to eat prey, such as mice, rabbits and deer. 'Their digestive system, which is very different to the human digestive system, is more than able to handle raw meat, offal and bones. Loving life: Owners Margaret and Patrick Evans say Baylie is 'a different dog' since losing a stone and a half on a new doggy diet of raw food. They believe his weight problems stem from rewards during training . 'In fact, they thrive on it and you need have no concerns over its suitability. 'We avoided beef and lamb and suggested lean raw meat like free range chicken, wild rabbit and turkey. 'Our treats are pure air-dried liver and dogs don't need very much to feel like they've had a treat. 'We also introduced a concept called Bone Sunday. We gave Baylie a beef knuckle bone to chew on all day and he didn't need anything else to eat. 'Because the bone marrow is so rich it's enough quantity wise. And the action of chewing is great exercise and a rewarding game. 'It makes sure he doesn't feel like he is on a diet and that food is still fun.' Baylie's owners believe his life-long weight problem stemmed from them giving him sweet treats to reward good behaviour at puppy training school. The treats continued into his adult life and he even learnt where they were kept and was spotted raiding the biscuit tin in the kitchen. His weight problem worsened as he started suffering from a joint problem called hip dysplasia affecting Labradors - and when he took a tumble while out on a walk he was left unable to move. Maragaret, 55, a car tyre production assistant said: 'We were encouraged to use biscuits as rewards but he was so good at everything we taught him we just had to carry on giving him treats. 'His weight just went on and on and on. 'But it got a lot worse when he slipped over one day when we were out for a walk in the woods. 'He injured his leg and couldn't walk very far so it made it really difficult to take him out for exercise. 'And because he has hip dysplasia it meant his recovery took a long time. 'He became sluggish and tired all the time and he just carried on piling on the pounds. 'I think it didn't help that he knew his way round the kitchen and exactly where we kept the dog biscuits. 'I knew his weight was becoming a problem but it wasn't until we got to the vet that we realised how big he had got. 'Once I took him to the vet and we realised how bad the problem with his weight was we knew we had to take action straight away.' Standing tall: Baylie struggled with a hip condition common in labradors and poor mobility worsened his weight problems. But losing weight has made him much more mobile . After spotting an advert for the trial of a new diet for dogs on facebook, Margaret signed Baylie up for the new regime - The Lucky Dog Weight Loss Plan. It meant - just like a human trying to fight the flab - swapping his usual processed food and sweet treats for low fat meats. After eight weeks he had lost eight kilos, going from 55kg - the weight of a small great dane - to 47. A much slimmer Baylie comes back to the beach after a swim in the sea during a walk on the beach . Shake it off: Baylie is able to enjoy a dog's life after shedding so much weight with his doggy diet of lean meat . Margaret added: 'We changed his diet straight away and went from tins and packets to all raw food. 'And because all of the food was delivered and it was a complete change it was really straightforward. 'Now he runs around and has bounds more energy. 'He loves a ball and is absolutely mad about going for a swim. We can't even run a bath without him trying to jump into the bathroom. 'He's like a completely different dog.' A different dog: 'Now he runs around and has bounds more energy', said owner Margaret who took him to the vets as soon as she realised how serious his weight problem was .
highlights: Labrador Baylie from Leeds suffers from hip problems - and a sweet tooth .
  Swapped sweet treats and processed food for raw meat, offal and bones .
  Owners say he is a 'different dog' since going on raw foods doggy diet .
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