Lets kick this fucker off - reversing out of a diet correctly

One of the many things that the internet is constantly plagued with is how you should "reverse" out of a diet successfully. I hate that term but for all intents an purposes people are asking how they should go on eating now that they have reached their body composition goal after dieting down to lose fat.

Of the concerns, the main one seems to be that their metabolism would have somehow of dropped, their thyroid output would be ruined and they will instantly turn back into the hippo they were before they started dieting. Most of these are pretty unfounded but it is clear on why people would think this given that conventional wisdom dictates you gain the weight back on after you come off a diet.

If only she'd just done a detox

The first issue is that of your metabolism being ruined by dieting. This is also governed by the thyroid as the thyroid is the main organ for dictating your metabolic rate. Luckily, "metabolic adaptations are a result of changes in body composition and variations in the metabolism of individual body components. Weight loss had a strong effect on improving insulin resistance in overweight and obese individuals". (Dengel. 1996; Niskanen. 1996).
That's great, because it means that as you diet down and get leaner, your insulin sensitivity increases and that's irrespective of whether or not you restrict carbohydrate. A low carbohydrate diet would improve that even more (McAuley. 2005). The implication of this is that when you eat carbohydrate, your body will more likely store it as glycogen in the muscles, rather than storing it as fat.

The practical applications? When you look at a large meta-analysis of 29 studies done on rapid fat loss, people only regained a small amount of what they had lost. They did regain however, but there was no further restrictions on diet placed afterwards- people just went back to their daily lives. What's interesting though is that people that lost a lot of weight very fast kept an average of 15 pounds off (29% of total fat loss) where as people that lost less weight kept an average of 4.5lb off which was 17% of the fat they had lost.
The key here is that the more fat you lose, the more you keep of and a higher percentage of it you keep off. Body fat set points are very real and it takes a big effort to unfuck the lifetime of gluttony that you've likely subjected yourself to. The leaner you get and the longer you stay lean, the leaner you're going to stay. Fast lost generally means fast gained and vice versa- but you can still make massive jumps so that it simply doesn't matter.

Muh thyroid

The next issue is that of the thyroid. It is true that low carbohydrate diets lower your thyroid output (5,7) and that a hypocaloric diet will do the same (5) but this should be of little concern. 

Firstly, after 3 days of carbohydrates being over 100g a day thyroid output increases (5,6,7) and secondly- the thyroid has the remarkable ability to store it's secretions (1) so you will have enough stored to continue release as you need it so long as you have plenty of iodine in your diet. You have a 2 week supply of iodide (2) so as long as you salt your food, you should be fine. The thyroid gland is unique amongst the endocrineglands because it stores large quantities of its secretory product (approximately 100 days worth). This means that deficiency can take a while to present clinically. (3)

Now that's out the way- how to apply this

Now that you've finished dieting down and rejoined the human race, your primary goal should be to push your caloric intake as high as possible while keeping fat gain as low as possible. This would seem like an impossible task only achieved by painstakingly increasing calories over the course of several weeks to gradually increase your metabolic rate or some other such nonsense. 

As I mentioned before, body fat set points are very real and your body will fight to go back to its former glory of fatassedness. The longer you stay lean and the leaner you get, the leaner you'll stay so I highly recommend staying lean for at least a month before you attempt to raise calories. Yes, this fucking sucks, especially as you've likely already spent 2-3 months to get to this point. However you're not out of the woods yet and it's your own fault for stuffing your face for a lifetime and now you're paying the price. Also, if you don't have abs yet then just forget about the entire thing- you're not lean enough to benefit in any way from this and should continue to diet down. Eating more will only result in weight gain again for you and the reality is to gain a decent amount of strength and muscle without your adipose ballooning out of control you need to start lean.

You should ideally be about this lean before attempting to enter a mass-gaining phase

For the sake of your own sanity, I'd recommend raising calories during this month. A ketogenic diet would be perfect for this. Whatever calories you used to get lean, I'd take your body weight in pounds and have that as grams of protein a day. Find some lean source of protein, find how much you need to eat to get that amount of protein in and see how many calories that is. Then, get the remainder of the calories from fats and add 250 Calories to whatever you were eating before. Nuts, peanuts, cream, eggs, fattier meats butter and oils are all great choices for the extra calories. You will likely be starving from dieting so I would recommend making a stew with plenty of vegetables, adding the fats into that and drinking the broth/juices when you're done eating it. I'd aim to keep your weight within half a kilo of your original dieted down weight doing this. At the end of the week, throw in a 3h cheat window where you eat what you want as your only meal for the day and increase your calories by 250 a week until either the month is up or your weight increases by half a kilo. Obviously your weight will go up after the carb window so you should be weighing yourself the morning of the carb -up.

After you've stayed lean for a month, your body fat set point should have reset a bit. You'll find now as you've stayed lean for a while, you'll be able to take advantage of your newly acquired insulin sensitivity. As such, your diet should consist of a lot of carbohydrate, moderate protein and as little fats as possible. Such a macronutrient ratio has been shown to be incredibly successful in muscle gain and a 4 week massive overfeeding of 800g carbohydrate a day showed a massive increase in muscle mass over a lower carb, higher fat diet (1.5kg vs 0kg) and a habitual diet with minimal fat gain (300g in 28 days vs 900g for the regular group) despite eating a 4,400kcal diet more than 1,000kcal over maintenance. (4)

This increase in muscle wasn't just glycogen either, at 800g of carbs a day with the average trainee at 77kg body weight, glycogen would be full after just the second day of carb loading. The regular carb group would have also had full glycogen, albeit at a slightly slower rate but did not see the same increase in muscle mass. 

I'd recommend really hitting the carbohydrate hard on your training days, especially around the training window as this is when you're going to be the most insulin sensitive. I don't see any reason to go above 4g/lb in grams of carbohydrate a day personally, you'll want to keep fats at under 0.1g/lb and protein at 1g/lb. So a 90kg guy would be eating 400g of carbs, 200g of protein and 20g of fats for 4180kcal a day. I'd keep this static for 4 weeks but you may be able to push this to 8 weeks, especially if you've never been fat in your life. 

On your non training days, I'd increase your protein and reverse the carbs/fats. You've just spent all that time getting insulin sensitive by dieting and it would be a shame to ruin that in 8 weeks of gluttony. You're not going to be as insulin sensitive if you're not training and your glycogen levels are going to be full from the massive amounts of carbohydrate you ate on training days so you may as well get the calories you need from alternate sources. You'll be getting plenty of calories on your high carb days also, so you should see a reduction in calories on your off days. I'd put protein at 1.5g/lb and make this half of your intake, carbs as low as possible and fats making up the same amount of calories as the protein. For our 90kg example, this would be 20/300/135 for 2500kcal.

Obviously, suggesting one target calories for everyone of a particular body weight of all activity levels is retarded, so you should use these as a base line and tweak it to your needs. I'd use waist measurements to dictate if you're getting fatter or not and play around with the amounts of carbohydrate on your training days and fats on your rest days.

Ketogenic dieting doesn't have to be shit

After 4-8 weeks you notice your waist increasing too much, reducing the carbs on your training days to 1.5-2g/lb should be suffice for replenishing lost glycogen and an increase in fats to make up the rest of your calories. Obviously experimentation if the name of the game here but you can rest easy knowing that you're not going to turn into the fat mess you once were.

Sources:
Dengel. 1996; http://www.ncbi.nlm.nih.gov/pubmed/8828680
McAuley. 2005 http://www.ncbi.nlm.nih.gov/pubmed/15616799
Anderson 2001 http://ajcn.nutrition.org/content/74/5/579.full
1. https://mcb.berkeley.edu/courses/mcb135e/thyroid.html
2. http://www.uta.edu/biology/wilk/classnotes/endocrinology/Thyroid.pdf
3. Murphy O'Neill; Crash Course Endocrinology 4th Edition
4. http://www.cabdirect.org/abstracts/20113206370.html
5. Pasquali R. et. al. http://www.ncbi.nlm.nih.gov/pubmed/7096916
6. Spaulding SW. et.al. http://www.ncbi.nlm.nih.gov/pubmed/1249190
7. Pasquali R et. al. http://www.ncbi.nlm.nih.gov/pubmed/6863849