If you have been dieting for a long time it can get very repetitive and exhausting mentally as well as the feeling of being on reduced calories. Having to track calories or be very mindful of how many calories you are consuming daily gets extremely tedious over time and causes many people to fall off their diet over time.
Sometimes in these situations it can be very beneficial to take a break from your diet. This doesn't mean go on a massive cheat week and consume a lot of unnecessary calories. You should approach your diet break sensibly without the stress of tracking or using whatever method you use to stay on track. The goals of your diet break should be to try and increase your energy levels in the gym by eating more calories, improve your hormone balance and recover mentally from your diet.
Everyone is different so diet break rules can change from person to person. However, most of the time when you are dieting for fat loss, carbohydrates will more than likely be the first macro nutrient you reduce. So when taking a diet break this is the macronutrient I recommend increasing when building up your calories. I would also recommend just keeping an eye on your weight. You are likely to see an increase in your weight slightly by a few pounds or so due to the extra water you will hold from the extra carbohydrates. A few pounds increase in weight is fine however if your weight is increasing rapidly you may be eating a little too much. I’ve had situations where I have put clients on a diet break and have seen a reduction in weight which is a great scenario but again everyone is different.
A planned week or 2 of extra calories will not make you fat if you are sensible. Even if you gain a little extra fat, if it means you stay on target over the long term I think a planned break is highly worth it. Don't be that person that gives up on the long term goal because the diet was getting hard. Take a break and return ready to smash it.