How exactly do cheat days work?

They don't work, at least for me. My deficit (1/2 pound per week at this point) is small enough that I can EASILY demolish it with abandon. Some days I eat more than others, but I always log it. Some weeks I have no deficit and don't feel like I really ever went that 'crazy.' Which is exactly why I have to log it all No point in lying to myself.

Yes, one cheat day can wipe out your weekly deficit. It just depends on how many extra calories you ate that day compared to your weekly deficit. It’s not that hard to eat an extra few thousand calories with a huge breakfast platter, big sandwich & chips for lunch, pizza, beer, and ice cream for dinner, if you’re not closely watching your portions. Easy to wipe out a 1-2 lbs deficit for the week!

I don't schedule cheat days, but if I feel like I need it (hunger level, energy level) I eat either maintenance or smaller deficit for a day. It doesn't ruin previous days, and I don't make up for it. I just consider it a break.

If you look at this "dieting" as a lifestyle change and not a sentence (with an end date) then it is easier to look at your eating habits in the long term, big picture, and not in the short term ("Oh my God I am going to gain it all back!) Relax!

It's all about the calories. Burn more, eat more to maintain your weight. Burn less, eat less to lose weight.

To gain a pound you have to eat 3,500 extra calories over what you burn per day.
To lose a pound you have to eat 3,500 less calories less than you burn a day.

To get an idea about what I am talking about, you have to know your your resting metabolic rate (or RMR), (the amount of calories that your body burns while you are at complete rest (i.e. reclining with muscles relaxed) to keep itself alive and digest food, but nothing else. More specifically, resting metabolic rate calories are burned to digest, absorb, and store the nutrients in the food you've eaten.

To raise that RMR (burn more calories) you have to exercise!

Calculator Formulas
Male (metric): RMR = [(13.75 x WKG) + (5 x HC) - (6.76 x age) + 66] x 1.1
Male (imperial): RMR = [(6.25 x WP) + (12.7 x HI) - (6.76 x age) + 66] x 1.1
Female (metric): RMR = [(9.56 x WKG) + (1.85 x HC) - 4.68 x age) + 655] x 1.1
Female (imperial): RMR = [(4.35 x WP) + (4.7 x HI) - 4.68 x age) + 655] x 1.1
where

HC = Height in Centimetres
HI = Height in Inches
WKG = Weight in Kilograms
WP = Weight in Pounds

If you suck at math, see this link:

http://www.shapesense.com/fitness-exercise/calculators/resting-metabolic-rate-rmr-calculator.shtml

______________________________________________________________________________________________________________

All that said, are you eating a calorie deficit / exercising just to lose weight (and are craving a cheat day)?

If that is the case, what would your maintenance calories be for your ideal weight? Would they be higher? If they are way higher (like more than 350 calories, then you are not eating enough for the exercising you are doing).

My experience has been that when I am vigorously exercising that there is a difference between anaerobic and aerobic exercise and they each do different things.

When we exercise aerobically our bodies use glycogen and fat as fuel. (I feel less hungry because my body is using stored fat as fuel).

When we exercise anaerobically glycogen is used as fuel. (I crave carbs because once all the glycogen has been depleted I hit a wall).

You may want to think about your macros also, depending on the type of exercising you are doing.

I tend to do better on less sugar and carbs, but that's me.

---

A book that I really like is by Covert Bailey, Fit or Fat, which is based on the exercise formula of Frequency, Intensity and Time - it's super cheap used and it goes over a lot of this stuff in very easy to understand language.