Best Dog Food for Overweight Dogs in the UK (2026)

At a glance

• Over half of UK dogs are overweight — it is the most common health problem vets see, and diet is usually both the cause and the most effective fix
• High-starch kibble drives weight gain even when portions are measured correctly — the carbohydrate load and processing method matter as much as calorie count
• Fresh food is more satiating than dry food — higher protein and moisture content means dogs feel fuller on fewer calories
• Excess weight puts direct pressure on joints and shortens the window before mobility problems develop — weight management is not just cosmetic
• Most dogs reach a healthier weight within three to six months of consistent dietary change and correct portioning

Why is my dog overweight even when I'm careful with portions?

Careful portioning is not always enough when the food itself is working against you. Weight gain is the most common health problem vets see in UK dogs, and the format of the food matters as much as the quantity.

Most dry kibble is 40-60% carbohydrate, and that starch is not there because dogs need it — it is there because the manufacturing process requires it to hold the pellet together. A dog eating perfectly measured portions of a standard kibble is still eating a diet heavily skewed toward starch, which drives the kind of blood sugar response that encourages fat storage over time. The guidelines on the back of the bag may say those portions are correct, and they are — for that food. They are not necessarily correct for a dog whose weight keeps creeping up despite everything.

There is also what happens to the food during processing. High-temperature extrusion damages protein in ways that make it harder for the body to use, so the dog extracts less nutrition per gram than the label suggests. That is part of why some dogs on kibble seem perpetually hungry even after a full bowl — they are not being greedy, they are responding to food that is not quite delivering what it looks like it should.

Which ingredients contribute most to weight gain in dogs?

High-starch fillers are the main culprit — maize, wheat, rice, pea starch, and potato, particularly when they appear near the top of an ingredient list. That placement matters because ingredients are listed in descending order by weight, so a food where starch features prominently is a food built around it.

Carbohydrates are not inherently the problem — dogs can handle them fine. The issue is quantity and source. Whole oats or brown rice in a fresh food recipe behave very differently to maize meal in extruded kibble. Cheap fillers digest quickly, spike blood sugar, and leave dogs hungry again sooner without having provided much in the way of real nutrition.

Fat tends to get blamed unfairly. It is calorie-dense, but it is also one of the most satiating things a dog can eat, and it is essential for coat health, hormone function, and absorbing fat-soluble nutrients. A named fat source like chicken fat or salmon oil is not a weight problem. The issue is more often rendered fat from vague origins combined with the starch load that surrounds it in lower-quality food.

Treats are worth looking at more carefully than most owners do. A medium-sized dog eating a daily dental chew on top of their meals might be adding 10-15% to their calorie intake without anyone registering it as food. It adds up quickly, and it is often the invisible variable when weight is not shifting despite careful portioning. Air-dried single-ingredient treats, where what is in them is obvious, are easier to account for.

Treats with fresh British chicken as the #1 ingredient

Get 40% OFF today

Use code: FRESH40

Why is fresh food better for overweight dogs?

Fresh dog food is more filling than dry food for the same number of calories, which makes the whole process of managing a dog's weight considerably easier — and less miserable for the dog.

Three things drive that difference. Fresh food contains 65-75% moisture compared to around 10% in kibble, and moisture contributes directly to feeling full. The protein is less processed, so the body uses more of it and hunger takes longer to return. And without the starch-heavy base that kibble requires, blood sugar stays more stable through the day, which means fewer of those mid-afternoon signals to start hanging around the kitchen looking hopeful.

The practical upshot is that a dog can eat fewer calories on fresh food and feel more satisfied than they would eating the same calories from a bowl of kibble. For a dog that needs to lose weight, that is not a small thing — a dog that is genuinely full is much easier to manage than one that is technically fed but clearly not satisfied.

Marleybones Lush Lamb and Sassy Salmon are built around named proteins with whole vegetables and no starchy fillers. 76% of Marleybones customers say switching has helped maintain or improve a healthy weight, and 47% noticed their dog had more energy after switching.

How do I calculate the right portion size for my overweight dog?

Portion size for a dog that needs to lose weight should be based on their target weight, not their current weight — feed to what they should weigh, not what they do weigh.

Find the daily amount recommended for your dog's target weight on the feeding guide for whichever food you are using, and stick to that. Weigh portions rather than scooping — cups and scoops are inconsistent, especially with fresh food, and small daily errors compound over weeks. A kitchen scale takes ten seconds and is the single most reliable thing you can do to make the process actually work.

Body condition scoring is a more useful ongoing check than scales. A dog at a healthy weight should have ribs you can feel without pressing, a visible waist from above, and a slight tuck behind the ribcage when viewed from the side. If the ribs have gone missing, the waist has disappeared, or the belly hangs straight, there is more to lose. Reassess every two to three weeks — muscle building can mask fat loss on a scale, but body condition shows you what is actually changing.

Aim for around 1-2% of body weight lost per week. Faster than that and you risk losing muscle alongside fat, which is the opposite of what you want. A 30kg Labrador on track should be dropping roughly 300-600g per week. If nothing has shifted after four weeks of consistent portioning, cut the daily amount by 10% and check again.

Support your dog’ s joints with a simple daily chew

Get 40% OFF today

Use code: FRESH40

What does excess weight do to a dog's joints and long-term health?

Each kilogram of excess weight puts roughly five kilograms of extra load through a dog's joints with every step. For breeds already prone to hip problems, elbow issues, or cruciate ligament damage, carrying too much weight does not just make things worse faster — it can be the difference between a dog that stays comfortable into old age and one that starts struggling in middle life.

Joints are the most visible consequence but not the only one. Overweight dogs are more likely to develop diabetes, heart disease, respiratory problems, and certain cancers, and research consistently shows that dogs kept at a healthy weight live significantly longer — in Labradors, the difference has been measured at around 1.8 years, which is substantial for a breed with a lifespan of around twelve years.

For dogs already showing stiffness or moving less freely,For dogs already showing stiffness or moving less freely, diet and joint support work best in combination. Joint health supplements can help with inflammation and cartilage, but they work much better when the load on the joint is also coming down. Getting weight off is the single most effective thing you can do for a dog with early joint problems — more so than any supplement on its own.

Which dog breeds are most prone to weight gain?

Labradors have a documented genetic mutation that affects the signal telling them they are full, which is why they will eat past satisfaction in a way most breeds will not. This is not greediness or bad training — it is a biological difference, and it means strict portioning and high-satiety food are genuinely non-negotiable for the breed rather than just good practice.

Cavalier King Charles Spaniels and Cocker Spaniels both tend toward weight gain in ways their owners often underestimate, partly because a small frame disguises how much extra weight is actually there. A Cavalier that looks only slightly rounded may already be 20-25% over a healthy weight. The same breeds that crop up frequently in food sensitivity and itchy skin conversations also tend to appear in weight management ones, which reflects a broader metabolic sensitivity that runs through these breeds.

Neutered dogs of any breed need around 20-30% fewer calories than intact dogs, and most feeding guides do not account for this. Using the standard guide for a neutered dog will overfeed them consistently, which is worth knowing if weight has been creeping up since the operation.

How long does it take for a dog to lose weight?

Most dogs lose weight safely at around 1-2% of their body weight per week — which means a dog that is 5kg overweight is looking at four to six months to get there. Longer than most people hope, but not as long as it feels with consistent portioning and no unplanned extras along the way.

The first couple of weeks often feel encouraging — water weight shifts alongside early fat loss, particularly when switching from kibble to fresh food, and the change can look more dramatic than the rate that will follow. After that it settles into a slower, steadier pace, which is normal and does not mean the approach has stopped working.

Energy and coat condition often improve before the scales do — 47% of Marleybones customers noticed more energy after switching, and that kind of visible change in how a dog moves and behaves is usually one of the first things owners spot. A dog that is brighter, more enthusiastic on walks, and moving more easily is responding to the diet even if the weight loss looks slow.

If nothing has changed after six to eight weeks of correct portioning, it is worth talking to a vet. Unexplained resistance to weight loss can occasionally point to thyroid issues or other metabolic conditions that need looking at rather than just adjusting the food.

“A complete game changer!!”

Get 40% OFF today

Use code: FRESH40

FAQs

How do I know if my dog is overweight?

The rib test is the most reliable quick check. Run your fingers along the ribcage — you should be able to feel each rib without having to press, but not see them. From above, there should be a clear waist. From the side, the belly should tuck up slightly behind the chest. If the ribs are hard to find, the waist has gone, or the underline is flat, the dog is carrying too much. Your vet can give a body condition score on a 1-9 scale, with most healthy dogs sitting around 4-5.

Is it safe to put my dog on a diet?

A gradual reduction of around 10-20% below their normal intake is safe for most healthy dogs and is the right way to approach it. Cutting food drastically is not safe and risks losing muscle alongside fat. If your dog has existing health conditions, is on medication, or is significantly overweight, talk to a vet before making changes — very low calorie diets should not be done without veterinary guidance.

Can I reduce my dog's portions without changing their food?

It will produce some weight loss, but it can also leave the dog genuinely hungry if what they are eating is not particularly filling to begin with. A dog on restricted portions of high-starch kibble is eating less but still getting a diet skewed heavily toward carbohydrates. Switching to something with more protein and less starch often means the dog can eat a satisfying amount while still losing weight, which is a much easier thing to sustain than simple restriction against a dog that is clearly not satisfied.

Are grain-free diets better for weight loss in dogs?

Not automatically. Most grain-free kibble just swaps grain for pea starch, potato, or lentils, which are similarly starchy and calorie-dense. Grain-free does not mean low-carbohydrate. What actually matters for weight management is the protein quality, the overall starch level, and the calorie density — not whether the bag says grain-free.

Does Marleybones help with weight management?

Marleybones meals are built around real proteins and whole vegetables with no starchy fillers, which makes them a much better starting point for weight management than standard kibble. They are high in the kind of protein the body can actually use, which supports satiety, and free from the cheap carbohydrate fillers that make blood sugar spike and drop. 76% of Marleybones customers say switching has helped maintain or improve a healthy weight. If you are not sure which recipe suits your dog, the Marleybones quiz will point you in the right direction.

Should I exercise my dog more as well as changing their diet?

Yes, but carefully. For dogs that are significantly overweight, especially those with existing joint issues, increasing exercise too quickly can cause injury. Start with shorter, more frequent walks and build gradually as weight comes off and movement improves. Exercise helps and builds muscle, but diet is doing most of the work in terms of actually creating the calorie deficit that drives weight loss.

“Such a relief to see her enjoying her food”

Get 40% OFF today

Use code: FRESH40