A little thing called “ad libitum” and why it means EVERYTHING if your goal is lasting fat loss…
Ad libitum is an important phrase used in literally tens of thousands of scientific studies on nutrition. It is latin for “at one’s pleasure.”
In the context of nutrition, “ad libitum” means a diet where the subjects (people or rodents or monkeys or whatever the experimental subjects are) are allowed to eat whenever they want and however much they want.
They can eat “at their pleasure,” so to speak.
Now, a NON-ad libitum diet means that the subjects were restricted to eating only a certain amount of food.
When it comes to fat loss, making the distinction of whether a diet is “ad libitum” or not makes a world of difference.
Well, if you’ve read my book, then you know that forced calorie restriction (non-ad libitum diets)–deliberately forcing yourself to have less food than you want, like in low calorie fat loss diets–is almost completely worthless for those trying to achieve lasting fat loss.
It DOES absolutely work to achieve short-term fat loss. In fact, nothing works better. So if your goal is simply to get ripped for a photoshoot or bodybuilding/physique competition (and you don’t mind blowing back up to your pre-diet body fat percentage after the photoshoot/competition), then you absolutely SHOULD be doing intense forced calorie restriction.
But if your goal is LASTING fat loss–and you want to lose fat, and KEEP IT OFF–then you should probably know that…
Virtually every long-term study ever conducted on forced calorie deprivation shows that it doesn’t work for about 95% of people to achieve lasting fat loss.
*** In reviewing the studies on dieting and weight loss, researcher Traci Mann notes that short-term weight loss from dieting does occur, but “these losses are not maintained… It is only the rate of weight regain, not the fact of weight regain, that appears open to debate.”
*** Here is what the very wise neurobiologist and renowned obesity researcher, Stephan Guyenet has to say on the matter: “If there’s one thing that’s consistent in the medical literature, it’s that telling people to eat fewer calories does not help them lose weight in the long term.”
*** The Biggest Loser TV show. Here we can clearly see what happens when people implement a diet and exercise program where they have professional guidance from trainers and nutritionists making sure they do things right and stick to their calorie deprivation programs. And without a doubt, it works like a charm—these people often lose 50, 75, or even 100 pounds following this “burn more and eat less” approach. So the problem of fat loss has been forever solved! It’s as simple as eating fewer calories and burning more. Case closed. Or wait, perhaps I spoke a bit too soon…As it turns out, over 90% of Biggest Loser participants regain all the weight they initially lose!
That pretty much sums up the studies on the effectiveness of forced calorie restriction in achieving long-term fat loss. Simply put, it doesn’t work very well.
Now, this does not mean that “calories don’t matter.”
In fact, they do matter! What it means is that conscious and forced calorie deprivation is not very useful if your goal is achieving LASTING fat loss.
The reason why it doesn’t work is that although we humans can fight against our biology for a period of time, ultimately our biology is going to win out. Our willpower to forcibly deprive ourselves and suffer through hunger pangs eventually wears down. The simple truth is that we can only sustain a period of forced calorie deprivation for a period of days, weeks, or a few months, before we give in to our body’s demands to eat how much it is telling us it needs.
Eventually, we ALL end up eating an AD LIBITUM diet!
In essence, pretty much everyone–outside of people in their short-term diet phases–is eating an ad libitum diet. We’re ALL eating “at one’s pleasure.”
Eating ad libitum is the normal and natural state for all animals–they don’t have to force themselves to eat this or not eat that, they simply eat when they are hungry and stop when they are full.
Whether we like it or not, eventually we all end up eating ad libitum.
So what matters is NOT whether a particular approach causes fat loss in the context of NON-ad libitum (i.e. forced low calorie) diets.
The only thing that matters is if a particular approach causes fat loss EVEN WHEN EATING AD LIBITUM!
Forced low calorie diets and crazy exercise routines (a la The Biggest Loser) work phenomenally well in the context of people who are competing in a competition for SHORT-TERM fat loss, while they have trainers and nutritionists looking over their shoulder, watching their every move and making sure that they stick to their diet and exercise routine every day. This is a NON-ad libitum environment. And in this environment, low calorie diets and crazy workout regimens work amazingly well.
But, as we already know, over 95% of people who adopt this same approach FAIL to achieve lasting fat loss when they are in ad libitum environments–which we all are in most of the time.
But this does NOT mean that all approaches to fat loss fail in the context of an ad libitum environment! No no!
In fact, we have numerous studies that have shown absolutely remarkable amounts of fat loss even when people are not forced to eat a low calorie diet and are allowed to eat however much they want!
*** One study found that just by changing the TYPES of food participants were eating, even while being allowed to eat however much food they want, participants spontaneously decreased their calorie intake from 2,478 to 1,584 calories and lost over 5 pounds of fat in the first 3 weeks alone. Again, that’s while eating however much they want! So this reduction in caloric intake is purely voluntary–which is the key to sustainable fat loss.
*** Another study found that simply by changing the types of food eaten, participants spontaneously and voluntarily reduced their caloric intake by hundreds of calories per day, such that they burned over 30,000 calories of their own body fat over the course of the first 12 weeks of eating this way.
*** Another study found that when eating a specific type of liquid diet, overweight people people eating ad libitum had absolutely remarkable amounts of fat loss (one very obese man lost 200 pounds in 255 days without hunger).
Of course, we also know that certain types of diets like the “cafeteria diet” promotes an increase of calorie intake by hundreds of calories per day and rapid fat gain.
And there are dozens more studies illustrating how simply altering the types of food one eats can dramatically increase calorie intake (and cause fat gain) or decrease calorie intake (and cause fat loss) without ever asking someone to consciously alter their calorie intake.
This is important because no one ever consciously decides to eat more calories and get fatter. It happens completely outside of awareness, right? When the obesity epidemic started 50 years ago, and people started eating 400 more calories per day than they had been in decades prior to that, it was not a conscious decision. We didn’t all wake up one day and decide to just start eating several hundred calories more each day.
It happened NON-consciously as a result of different types of foods being introduced into the food supply (and several other lifestyle factors). As these new foods were introduced into our diet, we simply started to unconsciously consume more total calories, and we got fatter. Again, all of this was happening outside of our conscious awareness due to our biology being affected differently by these new types of food–the ability of our brains to regulate our appetite in accordance with our biological need for food was disrupted and we started overconsuming calories.
Just as fat gain happens effortlessly when you eat certain kinds of foods, so too does fat loss happen effortlessly—without conscious willpower or forced deprivation or suffering–when we simply eat the right kinds of food.
And it is specifically this kind of fat loss–and ONLY this kind of fat loss–that lasts.
So, there is a hugely important distinction to be made here: There is a big difference between fat loss that comes from forced calorie restriction (non-ad libitum diets) and voluntary and non-conscious calorie restriction on ad libitum diets.
Think of it like this:
Forced calorie deprivation >>> Short-term fat loss >>> Metabolism Slowdown + Fatigue >>> FAT REGAIN
Voluntary/non-conscious decrease in calorie intake on ad libitum diet >>> No metabolism slowdown >>> LASTING FAT LOSS
Whether or not an approach causes fat loss while still allowing you to eat however much you want is the mark of an approach that works WITH YOUR BIOLOGY, rather than against it.
So if your goal is LASTING fat loss, forget about trying to lose fat by forcibly starving the body of calories, and JUST SAY NO to all the low calorie, low carb and juice fast “rapid fat loss” diets out there that rely on forced calorie restriction. That’s just a recipe for spinning your wheels, suffering through deprivation, and slowing your metabolism, only to ultimately pile all the fat back on.
For lasting fat loss, always remember that the key thing we’re after is fat loss in the context of ad libitum diets.
What are those factors that allow us to lose fat while eating however much we want? Stay tuned for the next installment to find out!
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