My dog is gaining weight?

I often walk Loona through the quiet lanes of our French city. She pauses to sniff, starts panting and sometimes I raise my eyebrows and ask: “Is our dog carrying a little too much weight?” Because yes, we live with a dog who has her own personality (reactive, naturally), and also a certain appetite. As a pet-parent, I’ve looked into what vets and researchers say: how to manage my dog’s weight, which diet path to choose, and why it matters.

In this article, I’ll walk you through the difference between a controlled diet and a restricted diet, what recent scientific studies show, including how diet links to life span and health span and how you can apply the findings to your dog.

Excess weight in our four-legged friends isn’t merely having “some extra fluff”: it’s linked with many health issues such as joint problems, diabetes, reduced lifespan, and a lower quality of life.

One landmark life-long experiment found that dogs on a long-term reduced-calorie diet lived significantly longer and got chronic diseases later. PubMed+3PubMed+3newscenter.purina.com+3

Another study in adult Labradors found that for each additional kilogram of body weight at age 10, the hazard of earlier death increased by 19%. PMC

So when you see your dog's waistline disappearing and her panting more after the short city-walk — it’s not just cosmetic. It’s a signal worth paying attention to.

Controlled diet vs Restricted diet — what do these terms really mean & what does research say?

Controlled diet

This is the sensible middle ground: adjusting the diet thoughtfully — reducing the daily calories to a safe level, choosing a purpose-formatted “weight management” food, increasing fibre or protein, distributing meals mindfully.

In one study of 48 Labrador Retrievers, dogs on such a controlled, moderate calorie reduction lost about 10% of their body weight, while dogs whose owners simply increased activity lost only about 2%. (Note: that study was more about weight‐loss than life span per se.) functionalbreeding.org+1

So a controlled diet is effective, realistic, and backed by research.

Restricted diet

Here we enter the realm of more stringent calorie reduction — often therapeutic, and to be handled with care. A famous example: the “Life Span Study” by Purina Institute on Labrador Retrievers. Dogs that were fed 25% fewer calories from puppyhood onwards had a median life span of ~13.0 years, versus ~11.2 years in the control group — that’s about +1.8 years (≈15–16%) longer life. Purina Institute+2Muller Veterinary Hospital+2

Beyond just living longer, those lean-fed dogs had delayed onset of chronic disease (hips, joints, insulin resistance) and better metabolic markers (lower triglycerides, insulin, glucose).

Formal note: While that study shows strong benefits, it’s conducted in a highly controlled environment, beginning in puppies, and doesn’t mean every dog should go on a 25% lifetime calorie cut. The key takeaway is: keeping your dog at an optimal body condition is crucial.

Notable Studies & Findings 

1. Purina “Life Span Study” (Labrador Retrievers)
   • In a landmark paired-feeding study of 48 Labrador Retrievers (starting at ~8 weeks of age), half the dogs were fed ~25% fewer calories than their paired littermates. Purina Institute+4newscenter.purina.com+4Irish Setter Club of America, Inc.+4
   • Key results:
     • Median life span for the lean-fed dogs was ~13.0 years vs ~11.2 years for the control group (~+1.8 years or ~15% longer). Purina Institute+3Purina Institute+3Muller Veterinary Hospital+3
     • The lean-fed dogs had delayed onset of chronic diseases (such as osteoarthritis, hip dysplasia) compared with the control dogs. For example: by 2 years of age hip dysplasia prevalence was ~50% less in lean-fed dogs. Purina Institute+1
     • The restricted diet dogs showed lower body fat, lower serum triglycerides, insulin and glucose concentrations. PubMed+2Irish Setter Club of America, Inc.+2
   • Why this is relevant: It shows that lifelong maintenance of lean body-condition (or modest caloric restriction) can extend both quantity and quality of life in dogs.
2. Association Between Body Condition & Lifespan (Client-Owned Dogs, 12 Breeds)
   • A retrospective study involving 12 dog breeds found that dogs classified as overweight had a shorter median life span compared to dogs in a normal body condition. PMC+1
   • Though the magnitude varied by breed, the direction was consistent: overweight body condition was negatively associated with lifespan.
   • Importance: This supports that even in “real-world” companion dogs (not just laboratory conditions) body condition matters for longevity.
3. Controlled Diet vs Physical Activity for Weight Loss (Pet Dogs)
   • A 2018 randomised clinical trial found that for overweight pet dogs, dietary caloric restriction (therapeutic weight-loss diet) achieved a median ~10% body-weight loss, whereas increased physical activity alone achieved ~2%. PubMed
   • Although this study focuses on weight loss rather than lifespan directly, it provides scientific backing for the “controlled diet” approach in dogs and shows that diet is more effective than exercise alone in this context.

What you can do at home 

a) Assess the situation

• Use a Body Condition Score (BCS) for your dog (commonly a 1-9 scale): feel the ribs (should be palpable but not prominent), look from above & side for waistline.
• Chat with your vet to define a realistic target weight for your dog's breed, age, activity.
• Check when you last weighed her/him- set a baseline.

b) Choose a suitable diet

• Pick a “weight management” or “ideal weight” adult-dog version
• Ensure it’s high in quality protein, moderate in calorie density (kcal/kg), contains enough fibre.
• Make sure all essential nutrients are still there, research has shown even in weight-loss studies, some nutrients (e.g., choline, selenium) could be slightly lower. functionalbreeding.org
• Don’t just choose “light” food and keep the same quantity — measure portions carefully.

c) Control calories & portion size

• Use your kitchen scale for accuracy — eyeballing often leads to over-feeding.
• Avoid “grazing” or too many tasty leftovers / table scraps (Loona knows when I sip my tea and offer a nibble!).
• Spread meals or use enrichment devices (sniff mats, treat-balls) to slow down the eating process and engage her mind.

d) Activity & enrichment

• While diet is more effective for weight loss than exercise alone (see research), physical activity still matters for muscle mass, cardiovascular health and mental well-being.
• Indoors: puzzle feeders, slow-feed mats, interactive toys - especially if the weather or reactivity means indoor time.

e) Monitor & give it time

• Aim for gradual weight loss:  for many dogs, something like 0.5-2% of body-weight per week is a sensible target (but always vet-led).
• Weigh regularly (every 2-4 weeks) or check girth measurements.
• Keep a log in your phone or a printable checklist (we’ll design one soon for Paws in Cher!).
• If progress stalls after ~2-3 months, review with vet: perhaps adjust calories, evaluate underlying health issues (e.g., hypothyroidism, Cushing’s).
• Celebrate the “still” small wins: better leash behaviour, less panting after a stroll, visible waistline.

What many pet-owners get wrong & how to avoid it

• Saying “let’s skip meals” or extreme cuts: Drastic reductions risk muscle loss, nutritional deficiency, behavioral problems. The Labrador study warns of side-effects if not monitored. PubMed
• Relying on activity alone: The weight‐loss study shows increasing exercise by itself achieved modest -2% loss, vs diet which achieved more.
• Estimating food by “looks” rather than measuring: Portion creep happens fast (extra bits, snacks, treats).
• Ignoring underlying causes: If your dog has metabolic disease, endocrinopathy or pain limiting activity — diet alone may not solve it.
• Expecting immediate results: Weight loss takes time. Owners who gave up early often see less success. Research shows about half of dogs reach “ideal” weight in long-term studies. Purina Institute

Conclusion 

Watching your dog’s weight is not just about how they look in that charming French background or how they fit in the car on dog-walk days. It’s about health, mobility, joy, and years of shared sunsets (for us in our French medieval lanes).

So if you notice your dog's waistline fading, or them panting more after the gentle stroll, this week’s your nudge:

• Check their Body Condition Score.
• Log their current ration.
• Plan one new route in the city.
• Set a “weigh-in” mark in four weeks.
  And yes — I’m working on a free downloadable “Dog Weight & Diet Checklist” for Paws in Cher readers. Keep an eye on that if you’d like a printable to track progress.

Over to you: What diet strategy have you tried with your dog? Has it worked? What surprised you? Share your experience by commenting below or on Instagram/TikTok with #PawsInCher — because we’re all in this fur-filled, medieval-wall’ed, tea-steeped adventure together.