Friday, February 26, 2016

Will your cat still love you if you put him or her on a diet?

Obese cat
There are only two treatments for excess weight in cats: less calories in (diet) and more calories out (exercise).The weight here is in kg, so this male indoor cat was almost 12kg.

Ever considered putting your cat on a diet? Worried how your cat might respond? According to reports, some owners believe their cats will be vindictive if their calories are restricted. But a recent report found that cats exhibited more affectionate behaviour when fed a calorie restricted diet. Some reports have gone so far as to declare “cat’s won’t hate you” if you diet them. How will this impact on the human:feline bond? Let’s break it down.

First, the background. Part of the issue of course is how we keep cats. So why do cats get fat in the first place? We confine them and that’s quite a reasonable thing to do – for their safety and that of prey species. We’re not in the midst of a rodent plague, so we don’t need cats out hunting. In the wild they’d ideally subsist on a diet of 12 mice each day - but each mouse has to be caught, which 
requires expenditure of calories.

Instead, we serve our cats calorie-rich meals. Risk factors for obesity in cats include living in an apartment (not much room or incentive to exercise), being the only cat in the household (no one to play or fight with), being male, being castrated (no testosterone to stimulate behaviours associated with mating, such as going out and looking for a partner, getting into scraps with other potential partners and so on), and being fed a prescription diet (high nutrient density). 
Ad-lib feeding is also a risk (and so common with calorie-dense, dry foods).

So how come people don’t just put overweight cats on a diet? After all, we control what they eat. Unlike people, they can’t duck off to McDonald’s or stash some Maltesers when we’re not looking (they can, however, get into your stash of Maltesers if you’re not careful).

Well, if you’re asking that question perhaps you’ve never experienced a hungry cat. As the authors of the study note, pre-feeding behaviours include begging, following meowing, and pacing. These can be seriously disruptive. For example, if I want to make it to the bathroom in the morning before feeding the cats, I have to navigate the hallway while two meowing cats simultaneously figure-eight around my legs, while crying loudly, without tripping over. If I happen to hit snooze on the alarm clock, I am nudged with a closed paw. Hit it again and the claws come out. That or a three legged cat dive-bombs me from the top of the wardobe. I reward this behaviour by waking up, getting out of bed, and…once I get down the hallway…feeding him.

Let’s go back to the lab. For the study, they enrolled 58 obese cats and fed each cat one of three diets (all equal calories) – a high-fibre diet; a low-carb, high protein diet; and a control diet formulated to maintain weight in adult cats. They compared weights at day 1, week 4 and week 8. They also compared behaviours at weeks 4 and 8. They looked at pre-feeding behaviours: prefeeding begging, following, meowing and pacing, as well as post-feeding behaviours: jumping in the owner’s lap, purring, resting, sleeping and visiting the litter tray. The owners were asked whether they thought their cat’s affection had changed with the feeding of the new diet.

The great news was that 3 out of 4 cats had weight loss recorded at 8 weeks, with the high-fibre diet fed cats losing more weight over 8 weeks.
BUT…the pre-feeding “blackmail” was dialled up, regardless of the diet. Cats didn’t necessarily beg for longer, but when they did it, they did it more. However, they also ramped up the post-meal behaviours- most notably, jumping on their owners’ lap. Owners felt their cats were more affectionate.
The way this story is being reported is that this is great news – owners will feel more bonded with cats because they showed more post-feeding affection. Not much has been said of the amping up of the pre-feeding behaviour. I speak to owners of cats with polyphagia – an increased appetite –  due to conditions like thyroid disease and diabetes. The pre-feeding behaviour can occur frequently and can be extremely difficult to cope with (these cats are usually much easier to live with when they are treated).

Interestingly, owners saw pre-feeding begging as affectionate behaviour. So whether or not this is factored into overall increase in affection documented is hard to say.

Anyway, it’s great to see a study that addresses both nutrition and behaviour and raises important questions about the way we feed the feline members of our household.

You can listen to a podcast of VetTalkTV’s Brian and Kaye chatting with me about this and another cat food study at this link here.


Levine ED, Hollis NE, Schoenherr B & Houpt KA (2016) Owner's perception of changes in behaviours associated with dieting in fat cats. Journal of Veterinary Behaviour 11:37-41