A few years back, cheat days were the rage. Initially the idea of "stepping out" on your diet was met with skepticism, but as research emerged supporting the idea that taking a day off could actually speed the rate of fat loss, people increasingly jumped on board.

Cheating isn't a new idea by any stretch, nor is it going anywhere. In 1999, Bill Phillips, borrowing an idea from sometimes employee sometimes partner TC, put forth the idea of the "free" day in the bestselling newbie bible Body-for-LIFE.

More than a decade later, in his own bestseller The 4-Hour Body, Author Tim Ferriss again extolled the virtues of the cheat day. In between those two bestsellers (2002), T NATION published The Cheater's Diet by Joel Marion, and since then Joel has followed with a number of highly successful programs that incorporate cheat days.

However, recently cheat days have come under fire. A number of respected coaches, including a few T NATION top guns, have spoken out against cheat days, despite their apparent popularity.

Of course, what's popular isn't always right, but to dismiss cheat days completely out of hand seems a bit rash.

This is especially true when some of the arguments against cheat days are founded in illogical reasoning and sensationalistic statements–which is what's been going on.

The main purpose of this article is to defend cheat days. But rather than present a stack of before and after pictures or testimonials supporting their efficacy, we'll explore the most common argument against cheat days, and ascertain whether it even holds water.

To Begin at the Beginning – Why Cheat?

Let's first cover the theory behind cheat days and why they've been included in nutrition plans to begin with.

The theoretical benefits of cheat days are:

Increased thyroid hormone output. When in a caloric deficit, underfed individuals produce less T3 and T4–both important thyroid hormones that play roles in the regulation of metabolic rate. A cheat day or strategic overfeed is used in part to increase these hormones.

Increased 24-hour energy expenditure. A caloric surplus from a cheat day causes the body to upregulate basal metabolic rate (BMR). Some studies have shown an increase of 9% above baseline, and it's hypothesized that more is possible.

Increased serum leptin levels. The big one that most harp on. Leptin levels drop while in a caloric deficit (lasting as little as 72 hours), and a periodic bump in leptin coming from a cheat day has several benefits including increased thyroid output, increased energy expenditure and BMR, and overall increased thermogenesis.

Those are the physiological and hormonal benefits of cheating. Of course, there's the psychological benefit of being able to take a day off from your diet; eat whatever you like and be comfortable in the knowledge that you'll still get lean. It's hard to quantify how much that actually helps, but the majority of folks who opt to use cheating protocols cite this as one of the most significant benefits.

The First Problem

The issue that arises in any discussion of cheat days is that from a purely scientific or research based standpoint, the studies are conflicting and the conclusions that are most solid aren't always applicable.

Essentially, the idea of using cheat days is to get leptin-depleted individuals to increase leptin levels, which will result in all the benefits listed above. That would be great, but the problem is that often those using cheat days simply aren't leptin-depleted; at least, not insofar as their metabolic rate is slowing to a significant degree.

Or so the doubters would posit. Two points to consider:

Any drop in metabolic rate is unacceptable. As T NATION contributor Shelby Starnes wrote, a 6% decrease can slow things down to a degree that the dude simply can't abide. This is especially true at higher levels of development, and even more so when a contest or deadline is approaching. Those who aren't depleted in the technical sense are keeping calories too high on non-cheat days. This means that while they're still getting some benefit of cheating, they're not optimizing progress. This can be–and is–true of any diet, and so for the purposes of deciding whether cheating protocols work, it must be discarded as user error. Problems with the client are not the fault of the method.

The Fact Is...

Cheat Days WORK. They just work. Even if there is evidence to suggest that cheat days or periodic overfeeding doesn'tenhance the rate of fat loss, at this point there's too much anecdotal evidence to say that theyslow fat loss.

I've worked with hundreds of clients, and while I'm not testing leptin levels, I know that cheat days DO NOT slow progress. And so, if they don't hurt and probably help, what's the problem?

The Second Problem: The Illogical Argument

There's a growing trend to argue against cheat days based NOT on any physiological basis but rather a psychological one, comparing cheating to addiction.

I'm not kidding. I wish I was.

The illogical argument is as follows:

"Telling a dieter to have a cheat day is like telling an alcoholic that it's okay to binge drink one day per week."

Actually, no it's not.

That argument ONLY holds water if a few things are assumed as fact:

(Cheat) foods are addictive.

People who eat cheat foods are addicted to them.

Eating cheat foods one day per week perpetuates the addiction.

Now, it's true that for some, food can be addictive, and as such it can be used and/or abused for comfort and the like. I've no real issue with the first assumption, in theory.

The problems start to arise when we get to the second assumption, that people who eat cheat foods are (all) addicted to them.

That's ludicrous. Fact is, basing an argument on such an assumption is to commit a logical fallacy known as "affirming the consequent."

The assumptive argument would be, people who are addicted to junk food eat junk food; therefore anyone who eats junk food is addicted to it.

Clearly, this isn't accurate.

To go back to the example of alcohol, the representation of this utter nonsense would be, alcoholics drink alcohol; therefore everyone who drinks alcohol is an alcoholic.

You can see where this is going.

As the saying goes, not all rectangles are squares. Not everyone who drinks is an alcoholic, and enjoying pizza once per week doesn't mean you're addicted to pizza or have fantasies of copulating on the counter at Papa John's.

The third assumption is that eating cheat foods perpetuates the addiction to cheat foods. This requires the second assumption to be true–that is, in order for it to even be considered, you'd have to accept that everyone who eats a little non-diet food is addicted to those foods.

Since it's quite clear that the second assumption is false, and the third relies on the second to be relevant, the third can't be true, either.

So, of the three assumptions that would NEED to be true in order for the original argument to work, two are logically invalid.

You don't have to be Leonard Nimoy to raise an eyebrow at that.

To be fair, there are folks who do battle serious issues with food. For these individuals, cheat days aren't a wise idea. However, as with any dietary protocol, there will always be certain populations that would be better served following a different approach. We can't allow dietary practices that are of value to many to be dismissed outright.

The Third Problem: The Abundance Argument

Another argument that's been used (again, comparing food to alcohol) is, "Even for non-alcoholics, is it a good idea to encourage excessive recreational drinking one day per week?"

Um, yes–that day is called Saturday, and it's the day when epic things occur and embarrassing pictures are taken.

Kidding, kidding.

Seriously, again this argument implies a strong assumption. It assumes that proponents of cheat days suggest excessive consumption of "bad" foods as the sole or even primary source of nutrition.

That simply isn't true.

First, there's no rule in any cheating protocol that states a person has to eat unhealthy foods on a cheat day. As long as the dieter gets in adequate carbs, fat and calories, it doesn't matter if it's from oatmeal and egg whites or oatmeal cookies and Egg McMuffins.

Clients can–and should–eat whatever they want. Most of them want to have some junk food, and that's fine. No one has ever published a diet involving a cheating protocol that suggests or requires that ALL calories be obtained from a drive thru window.

The cheat day is about freedom and choice, about removing the dietary mental shackles and enjoying yourself. Food choices and amounts are intensely personal, and the client chooses what's best for them.

To go back to the example of alcohol, I might tell a client it's okay to have a few drinks; that of course will mean different things to different people.

The point is that no coach recommends only bad foods for an entire day, and so the abundance argument is also irrelevant.

How (And When) To Cheat

So I've convinced you. You're going to start cheating on your diet again. You've stashed your MAG-10 Pulse Fast supplies and have scheduled an evening of dietary debauchery with your wingmen Ben and Jerry.

Hold up, soldier. You may qualify for a day's leave but the battle rages on. Here's how to use cheat days and still come away victorious.

If you're on a diet that doesn't specifically call for a cheat day or cheat meal, and you wish to add one in, assess progress first. If your progress has slowed for two weeks or more, a cheat day may help.

The first thing to consider is your overall level of caloric deficit.If you're not in a huge deficit, you don't need to cheat that often. The more you restrict calories, the faster leptin levels will drop and the more you'll benefit from a cheat day. Frequent cheat days generally only have merit for restrictive diets.If your diet doesn't force you to eat at a deficit of 50 calories per day or more, you don't need to cheat more than once or twice a month, and often a single cheat meal will suffice.A deficit of 750 calories per day or more generally allows you to cheat once per week, depending on your level of leanness.

The leaner you are, the more often you can cheat.Generally, if you're 10% or below, you can cheat once every 5-7 days. If you're 10-12%, every 7-9 days. If you're over 12%, you can cheat once every two weeks.

Those above a certain fat threshold – say 16% bodyfat, or anyone with more than 40 pounds to lose – probably don't need to cheat from a physiological standpoint. These people are better off with cheat meals, not cheat days, which should be used once every two weeks until progress slows. After that, a progression to one cheat meal per week is used.

If you're naturally prone to fat gain, don't cheat unless you're pretty lean (12%). Even then, start small.Use cheat meals and assess progress, and graduate to cheat days.

Along similar lines, ectomorphic guys can schedule one cheat meals during mass gaining phases a day to help them put on more weight. For these guys, I don't recommend cheat days but a single cheat meal every 3-5 days to get in some extra calories.

The basic "limit" guideline for ANY cheat (either meal OR day) is to not push past the point of satiety. Eat whatever you want, but don't intentionally stuff yourself. Stop eating whenyou're nice and full, not uncomfortable.

To make any cheat day more effective, I recommend having a fast day to follow the cheat. This will create a huge caloric deficit following the caloric overload. In essence, you get the hormonal benefit of cheating (enhanced metabolic hormonal output) as well as the hormonal benefits of fasting (increased Growth Hormone production). By pairing a "feast" with a fast, you get the best of both worlds.

Final Thoughts

The fitness and nutrition industry is in part dependent on debate of various topics–hotly debated ones get attention and that's good for everyone. While it's certainly acceptable to enjoy a debate and I don't mind defending the ideas of what I endorse, I take issue with the way those ideas are attacked.

Whether someone agrees with and recommends cheat days for their clients or readers should be based on their assessments of either the science or the practicality. It seems, in this case, the arguments are based on emotion rather than logic, and that does everyone a disservice.

Hopefully this article has shed some light on the issue, and helps you to decide–logically–whether you'd like to include cheat days in your diet.

Live well. And prosper.