First Week Feeding: 14 Days, 4 Meals, 60%

For the first 14 days, feed exactly what the shelter or foster was feeding, split into 4 meals a day, and start at 60% of the amount you think the cat needs. That combination prevents the 3 things that send new cats to a clinic in week 1: diarrhea from a fast food switch, vomiting from a single large meal, and 48 hours of quiet anorexia that nobody notices. Write intake down for 3 days before you change anything. Week 1 also sets the pattern for the first 30 days: cats that eat reliably by day 7 are the ones that settle by day 30.

Why the food stays the same for 14 days

A cat arriving from a shelter is already running 3 stressors: a new building, new smells and a disrupted social group. Adding a novel food on day 1 stacks a fourth. The gut flora shift from an abrupt switch typically shows up at 48 to 72 hours as loose stool, and loose stool in a stressed cat is the most common reason week-1 adopters call a clinic. Keep the original food for 14 days, then transition over 7 days in 4 steps: 25% new food for 2 days, 50% for 2 days, 75% for 2 days, then 100%. If stool loosens at any step, hold that ratio for 3 more days before moving on.

Ask the foster 4 questions before pickup: brand and exact formula, grams per meal, number of meals, and whether the cat eats wet, dry or both. Take a photo of the bag. If the shelter cannot tell you the brand, buy the closest match in protein source and fat level and treat the first 2 weeks as a transition, not a preference test.

Four meals a day, sized to body weight

Four meals is not sentimentality. A cat's stomach holds roughly 40 to 55 g of wet food per kilogram of body weight, and kittens under 16 weeks have limited room and fast metabolism, so 2 large meals produce vomiting 10 to 20 minutes after eating. Split the daily ration into 4 feedings at 7 am, 12 pm, 5 pm and 9 pm for the first 7 to 10 days, then drop to 3 meals by week 3.

Age and weight	Meals per day	Total per day, dry	Per meal
8 weeks, 700 g	4	40 to 45 g	10 to 11 g
12 weeks, 1.1 kg	4	50 to 55 g	12 to 14 g
16 weeks, 1.6 kg	4	60 to 70 g	15 to 18 g
6 months, 2.6 kg	3	85 to 95 g	28 to 32 g
Adult, 4 kg	2 to 3	55 to 65 g	20 to 30 g
Adult, 5 kg	2 to 3	65 to 75 g	22 to 35 g

Those grams assume a dry food at about 3.8 kcal per gram. Wet food at roughly 1 kcal per gram means 3 to 4 times the weight: a 4 kg adult eating 200 g of pate is eating the same calories as 55 g of kibble. Check the label, because a 4.5 kcal per gram food cuts the ration by about 15%.

Start at 60% and ramp over 7 days

Whatever the table says, serve 60% of it on days 1 and 2. A cat that has been eating shelter food on a shelter schedule often eats 30 to 50% less for the first 48 hours regardless of what you offer, and a full bowl that sits untouched turns into a food-safety problem at 4 hours in a warm room. The ramp: 60% on days 1 and 2, 75% on days 3 and 4, 90% on days 5 and 6, 100% from day 7. Remove wet food after 30 minutes and dry food after 12 hours.

Weigh the food, do not scoop it. A standard 240 ml measuring cup of kibble varies by 25 to 40% depending on kibble size and how it settles, which is the difference between 55 g and 75 g. A USD 12 kitchen scale removes the guesswork, and it doubles as the tool that tells you the cat is losing weight before you can see it. Food is usually 25 to 30% of a cat's annual cost, so a 15% overfeed is real money — the cost breakdown has the line items.

The 3-day intake log

Log 4 columns for 72 hours: time, grams offered, grams eaten, and stool score on a 1 to 7 scale where 2 to 3 is ideal. Add a fifth line each evening for water intake and 1 note on behavior, such as ate in the open or ate only under the bed. Three days is the minimum because a single day of picky eating means nothing, while 3 days of eating under 50% of the ration is a pattern worth a phone call. If the cat will only eat under the bed or behind the sofa, the problem is location, not appetite; the first 90 days with a shy cat walks through the 3-week version of that fix.

Numbers to act on: under 50% of the ration for 72 hours, no stool for 48 hours, or any weight loss above 5% of body weight in 7 days. In an overweight adult cat, 72 hours with almost no food carries a real risk of hepatic lipidosis, so do not wait a week to ask for help.

Water, bowls and the 20-minute rule

Place 2 water bowls in different rooms, at least 2 m from the food, and offer 1 wide ceramic bowl rather than a deep narrow one — whisker contact is a common reason cats drink less. Wet food already supplies 70 to 80% water, so a cat on pate drinks little and that is normal. Never restrict water in the first week, and skip the 20-minute post-meal play session if the cat ate fast; instead, feed 4 smaller portions and put a ping-pong ball in the bowl to slow intake.

Red flags: when week 1 needs a vet

Call within 24 hours for vomiting 3 or more times in 12 hours, diarrhea lasting more than 48 hours, or a cat that has not eaten in 24 hours. Go the same day for a distended abdomen with unproductive retching, labored breathing, or a kitten under 12 weeks that stops eating for 12 hours — small bodies have small reserves. Bring the 3-day log to the visit; it shortens the appointment and often avoids a blood panel.

Your 5-step plan for the first week

Photograph the foster's food bag on pickup and buy a 2-week supply of the same formula.
Weigh the daily ration on a kitchen scale and divide it into 4 portions before the first meal.
Serve 60% for 2 days, then 75% for 2, then 90% for 2, then 100% on day 7.
Record 4 columns for 72 hours: time, offered, eaten, stool score.
Book a vet visit for day 3 to 5, and take the log with you.

One number decides whether this week went well: grams eaten per day, tracked for 3 days, rising toward the table value. If it is falling instead, stop changing food and call the clinic.

Frequently asked

Can I switch a new cat to my own food right away?

No. Keep the shelter food for 14 days, then move in 4 steps of 25% over 7 days. An abrupt switch commonly produces loose stool at 48 to 72 hours, and diarrhea in a stressed cat is the top week-1 reason for a clinic call.

My cat eats only half the bowl. Should I free-feed?

For 3 days, yes, split into 4 small meals and leave dry food out for up to 12 hours. Track grams eaten. If intake stays under 50% of the ration for 72 hours, stop guessing and call the clinic rather than adding treats.

How do I know the amount is right without a scale?

You cannot, accurately. A 240 ml cup holds 55 to 75 g depending on kibble size, a 25 to 40% spread. Use a USD 12 kitchen scale, weigh the daily ration, and check weight weekly; a 4 kg adult should hold within 5% of that number.