Food: the line you can change
Food is the biggest line you control. It moves with weight, with calories and with the price per kilo. See this line on the bill

Wet vs dry cat food: the yearly sum
A 4 kg neutered cat needs about 238 kcal a day whichever way you feed it, but a pouch holds far fewer calories per kilo than kibble. On these two labels I'd expect wet to cost about seven times as much.
From the catalog
Dry dog food
James Wellbeloved Small Breed Adult Turkey & Rice 1.5 kg
Small dogs, trying a small bag
£9.99
£6.66/kg
£1.82 per 1,000 kcal
Pets at Home Complete Large Breed Chicken 15 kg
Large dogs, lowest cost per kg
£15.49
£1.03/kg
Royal Canin Mini Adult 4 kg
Adult dogs up to 10 kg
£23.89
£5.97/kg
£1.53 per 1,000 kcal
Pedigree Adult Complete Beef & Vegetables 12 kg
Adult dogs on a tight budget
£29.09
£2.42/kg
£0.69 per 1,000 kcal
Puppy food
James Wellbeloved Puppy & Junior Turkey & Rice 2 kg
Puppies up to 14 months
£10.39
£5.20/kg
£1.36 per 1,000 kcal
Wagg Complete Puppy Chicken & Veg 12 kg
Puppies on a tight budget
£16.29
£1.36/kg
£0.38 per 1,000 kcal
Lily's Kitchen Puppy Chicken, Salmon & Peas 7 kg
Puppies, premium grain-free kibble
£48.69
£6.96/kg
£1.83 per 1,000 kcal
Royal Canin Maxi Puppy 15 kg
Large-breed puppies, 2 to 15 months
£66.99
£4.47/kg
£1.18 per 1,000 kcal
Wet dog food
Lily's Kitchen Sunday Lunch Chicken 400 g
Grain-free tin, sold singly
£3.59
£8.98/kg
£7.61 per 1,000 kcal
Pets at Home Meaty Selection in Jelly 24 x 400 g
Cheap own-label wet food
£13.16
£1.37/kg
£1.83 per 1,000 kcal
Royal Canin Mini Adult in Loaf 12 x 195 g
Small dogs on wet food
£16.99
£7.26/kg
£7.91 per 1,000 kcal
Forthglade Complete Duo Lamb & Turkey 12 x 395 g
Grain-free trays for adult dogs
£21.49
£4.53/kg
Dry cat food
Pets at Home Dry Adult Cat Food Chicken & Veg 4kg
Cheap own-label adult bag
£5.38
£1.35/kg
£0.36 per 1,000 kcal
Whiskas 1+ Adult Dry Cat Food Chicken 1.9kg
Adult kibble in a small bag
£5.99
£3.15/kg
£0.84 per 1,000 kcal
James Wellbeloved Senior Cat Chicken 1.5 kg
Senior cats, small bag
£16.79
£11.19/kg
£2.78 per 1,000 kcal
Purina ONE Adult Dry Cat Food Chicken 3kg
Mid-priced adult food, chicken first
£16.79
£5.60/kg
£1.52 per 1,000 kcal
Kitten food
Pets at Home Dry Kitten Food Chicken & Veg 2kg
Budget dry food for kittens
£2.89
£1.45/kg
£0.39 per 1,000 kcal
Whiskas Kitten Wet Cat Food Poultry Feasts in Jelly 40 x 85g
Wet pouches for kittens
£13.75
£4.04/kg
£5.12 per 1,000 kcal
Hill's Science Plan Kitten Dry Cat Food with Chicken 1.5kg
Calorie-dense dry kitten food
£15.79
£10.53/kg
£2.48 per 1,000 kcal
Wet cat food
Pets at Home Wet Adult Cat Food in Jelly Selection 48 x 100g
Own-label bulk box of pouches
£9.49
£1.98/kg
£2.25 per 1,000 kcal
Lily's Kitchen Tasty Cuts Wet Adult Cat Food in Gravy 8 x 85g
Grain-free tins in small pack
£9.59
£14.10/kg
Applaws Fish Selection in Broth 12 x 70 g
Topper for a complete dry food
£12.19
£14.51/kg
Whiskas 1+ Adult Wet Cat Food Mixed Menu in Jelly 40 x 85g
Everyday adult pouches
£13.75
£4.04/kg
£5.54 per 1,000 kcal