Say this all the time.
Lets call it 20 cals for sauce with a meal. 20 cals for some milk in a drink. Or some kind of drink.
40 cals a meal. 240 cals extra a day.
1680 calories extra a week.
6720 calories extra a month.
Thats almost 2lb of fat you didn’t lose. Around 24lb fat in a year.
That’s for just ketchup and some milk/drink each meal….
The reality is probably much greater.

It is abnormal to see weight gain on low calories or calorie deficit.

All adds up:
How much milk do you use with your tea/coffee, what kind of milk is it and is there anything else that you do, such as Starbucks coffees, drink alcohol (wine, alcopops, etc), add sauces when cooking (such as sweet and sour, Mexican, Bolognese, you name it), finish food of kids plates, health bars, syrups, grazing on fruit, nuts/nut butters, etc.

Common things people do without realizing the impact.

Great practice is to check thyroid and had full blood tests to rule out any conditions.

How many training sessions one does per week, cardio total amount in minutes, etc.

Do you use digital scales to measure food or averaging weight?

One thing people don’t see is this, especially in women.

A woman around 35-40 at around 170cm will need around 1600 calories to diet at 20% deficit.

However if they’ve dieted a while your metabolism may have slowed a further 15%.

This means you’d need 1360 cals to successfully be dieting.

However if you eat as I demonstrate above eating an extra 20 cals sauce and 20 cals drink a meal you’ll have ZERO deficit when consuming an extra 40 calories a meal/240 cals a day. You won’t be burning ANY fat as you’re matching calories in by calories out.

This is why you’ll often see people say “i’m on really low calories but seeing no results”.

You have no results not because of plan being wrong, but wrongly following the plan by adding a small amount of calories in each meal in a manner you don’t realise.

Harsh but its how it is!