I suspect that if your primary goal is weight loss or improving your health, you're better off just sticking to a healthy eating plan all of the time and NOT giving yourself planned occasions to, say, eat a cheesecake, or whatever.
But if your primary goal is a happy life, then maybe some indulging is worth it. Again, it depends on a few things - how healthy are you? If you're very sick or very obese, the tradeoff of the occasional piece of cheesecake might not be worth it. If you're fairly lean and healthy, it's a lot harder to argue that any food should be absolutely forbidden, especially if you're personally capable of indulging in moderation.
So let's assume that you are either one of those people who can't bear the thought of never having a treat again OR you're close enough to your health and body composition goals that the occasional treat is worth it (just on a cost-benefit analysis).
The way to think about cheating, or treating, is to maximize the value to cost ratio of what you indulge in.
Let me give you an example.
My kids come home from Halloween trick or treating every year with a sack full of cheap candy - things like Milky Way bars, Reese's Peanut Butter Cups, Hersheys chocolate - that sort of thing. Nothing wrong with any of it, and I'm okay with my kids indulging. However, they rarely want even half of their candy, so I'm left with a vast quantity of low cost chocolate that is mine for the taking. But I don't really like milk chocolate all that much - I mean it's fine, but it's not the sort of thing I personally crave when it's not in front of me. So I sometimes end up eating thousands of calories worth of crap that I didn't really want, except it was in front of me and available. I never really enjoy it all that much, and I feel like shit for days afterwards.
Compare that to another situation. I went to a wine bar with my lovely fiancee. She was hungry so we got a cured meat plate. It came with small pieces of mini toasted french bread. I made little stacks of cured meats and bread, which I ate with a flight of bold reds assembled by the wine store.
Guess which 'treat' I enjoyed more? And guess which one probably did more damage to my health?
That's the secret: Maximize how much your cheat or treat contributes to your happiness and minimize how much damage it does.
Here are some simple guidelines:
- Social over Non-Social. You will enjoy your indulgence more if it's shared - and you'll get the added benefit of being in a social situation and not having to say no to the treats being shared.
- Quality over Quantity. Many people find that a really high quality food item is more satisfying. People don't usually binge eat on great chocolate - they eat entire bowls of M&M's. So when you can, treat yourself to the highest quality item you can afford, not the one that provides the most calories per dollar spent.
- Starches over Sugar. If you have a serious sweet tooth, eat sweets. But if you just need a treat and you are flexible, steer yourself towards, say, a tray of roasted sweet potatoes (crazy delicious) or even french fries over, for example, ice cream or a cheesecake. There is just nothing good about sugar.
- Nutrients over non-Nutrients. Pick the food items that have some nutritional value over those that don't. A ribeye is better than a bowl of Gummi Bears.
A couple of more supporting ideas:
- If you KNOW you're going to indulge, do a hard hypertrophy workout beforehand. You might as well use those calories to heal up from a muscle fiber destroying, high volume, bodybuilding style workout. I can't promise that all the excess will go into your biceps, but some will.
- Once you decide to cheat or treat, DO NOT let yourself feel guilty about it. Savor it, then get back on the bandwagon of healthy eating.
Some people should stick to a healthy eating plan 100% of the time - those who are ill, athletes near their competition seasons, the very obese. Look, if you have to lose hundreds of lbs., just go without the crappy food for a while! But if you're closer to your targets, you might be happier indulging once in a while. Just make it count, savor it, and then get back to a sustainable, sensible diet.