summarize: Most of my patients are already on some sort of “diet” when they come
to me. One thing that almost all of them have in common is that they are
dissatisfied with the results.
I can empathize. During residency, when I was actually even fatter than
Not-Thin Peter, I tried a vegan diet for a while. Theoretically, going vegan
should have made it easy to lose weight, simply because you have to chew
your way through an awful lot of salad to match the caloric content of a
ribeye. But in reality, I was taking most of my meals in the hospital, so that
meant a lot of chips and other snacks, and a veggie sub every day for lunch. I
didn’t lose a single freaking pound in six months. Looking back, the problem
should have been obvious. While I was technically following a virtuous
“vegan” diet, I was basically eating a bunch of junk food that just didn’t
happen to contain animal products. In other words, I was on a vegan version
of the SAD, the Standard American Diet.
Even going vegan is not enough to free you from the clutches of the SAD.
It is our default food environment, occupying the middle of the grocery store:
the boxed and frozen and bagged bounty of an agricultural system that
produces subsidized corn, flour, sugar, and soybeans by the megaton. On one
level, it’s brilliant, a solution to four problems that have plagued humanity
since the beginning: (1) how to produce enough food to feed almost everyone;
(2) how to do so inexpensively; (3) how to preserve that food so it can be
stored and transported safely; and (4) how to make it highly palatable. If you
optimize for all four of these characteristics, you’re pretty much guaranteed
to end up with the SAD, which is not so much a diet as a business model for
how to feed the world efficiently. Two cheers for modern industrial food
systems.
But notice that a fifth criterion is missing: how to make it harmless. The
SAD was not specifically intended to do harm, of course. The fact that it does
harm most of us, if consumed in excess, is a consequence of the four points
above colliding with millions of years of evolution that have optimized us to
be highly efficient fat-storage vehicles. It is an unfortunate externality of its
business model, sort of like with cigarettes. Tobacco manufacturers set out to
make a lot of money from a plentiful agricultural commodity, but the solution
they devised, the cigarette, had an unfortunate side effect: it slowly killed the
customer.
The elements that constitute the SAD are almost as devastating to most
people as tobacco when consumed in large quantities, as intended: added
sugar, highly refined carbohydrates with low fiber content, processed oils, and
other very densely caloric foods. I should note that this does not mean all
“processed” foods are bad. Almost everything we eat, aside from fresh
vegetables, is processed to some degree. For example, cheese is a processed
food, invented as a way to preserve milk, which would otherwise spoil quickly
without refrigeration. What we’re really talking about, when we talk about the
SAD, is junk food.
The basic problem we face is that, for perhaps the first time in human
history, ample calories are available to many if not most people on the planet.
But evolution has not prepared us for this situation. Nature is quite happy for
us to be fat and frankly doesn’t care if we get diabetes. Thus, the SAD foils
our key objectives with regard to nutrition: it induces us to eat more than we
need to, becoming overnourished, while its preponderance of low-quality,
ultraprocessed ingredients tends to displace other nutrients that we need, such
as protein, to maintain optimal health.
The SAD disrupts the body’s metabolic equilibrium. It places enormous
strain on our ability to control our blood glucose levels, and causes us to store
fat when we should be utilizing it. The leading source of calories that
Americans consume is a category called “grain-based desserts,” like pies,
cakes, and cookies, according to the US Department of Agriculture. That is
our number one “food group.” If we consume a bunch of grain-based desserts
in a Cheesecake Factory binge, our blood glucose levels will surge. And if we
do it over and over and over again, as we saw in previous chapters, we will
eventually overwhelm our ability to handle all those calories in a safe way.
The SAD essentially wages war on our metabolic health, and, given enough
time, most of us will lose the war.
The farther away we get from the SAD, the better off we will be. This is
the common goal of most “diets”—to help us break free of the powerful
gravitational pull of the SAD so that we can eat less, and hopefully eat better.
But eating less is the primary aim. Once you strip away the labels and the
ideology, almost all diets rely on at least one of the following three strategies
to accomplish this:
1. CALORIC RESTRICTION, or CR: eating less in total, but without attention to
what is being eaten or when it’s being eaten
2. DIETARY RESTRICTION, or DR: eating less of some particular element(s)
within the diet (e.g., meat, sugar, fats)
3. TIME RESTRICTION, or TR: restricting eating to certain times, up to and
including multiday fasting
In other words, if you are overnourished, and statistically speaking about
two-thirds of us are, you will need to apply at least one of these methods of
caloric reduction: deliberately tracking (and reducing) what you eat; cutting
out certain foods; and/or giving yourself less time in which to eat. That’s it.
Breaking down our approach to nutrition to these three strategies allows us to
speak about dietary interventions more objectively, instead of relying on
labels such as “low-fat” or “Mediterranean” that don’t tell us very much. If we
modify none of these variables—eating whatever we want, whenever we
want, in as great a quantity as we want—we end up right back at the SAD.
Each of these approaches has its pros and cons, as I’ve observed over a
decade of working on nutrition issues with countless patients. These will be
covered in more detail below, but here is the tl;dr:
1. From the standpoint of pure efficacy, CR or caloric restriction is the
winner, hands down. This is how bodybuilders shed weight while holding
on to muscle mass, and it also allows the most flexibility with food
choices. The catch is that you have to do it perfectly—tracking every
single thing you eat, and not succumbing to the urge to cheat or snack—
or it doesn’t work. Many people have a hard time sticking with it.
2. DR or dietary restriction is probably the most common strategy
employed for reducing energy intake. It is conceptually simple: pick a
type of food, and then don’t eat that food. It only works, obviously, if that
food is both plentiful and significant enough that eliminating it will create
a caloric deficit. Saying you’re going on the “no lettuce” diet is pretty
much doomed to fail. And you can still overeat while adhering perfectly
to a particular DR, as I found out when I attempted to go vegan.
3. TR or time restriction—also known as intermittent fasting—is the latest
trend in ways to cut calories. In some ways I think it’s the easiest. When I
was a cyclist, and I was trying to drop that six final pounds from my
already very light (for me) frame, this became my jam. I would allow
myself only one meal per day, despite doing about three hours per day of
training. But this can still backfire if you overeat. I have, much to my
amusement, watched patients gain weight on a one-meal-a-day approach
by turning their meal into a contest to see who could eat the most pizza
and ice cream. But the more significant downside of this approach is that
most people who try it end up very protein deficient (we’ll cover protein
needs later in this chapter). One not uncommon scenario that we see with
TR is that a person loses weight on the scale, but their body composition
alters for the worse: they lose lean mass (muscle) while their body fat
stays the same or even increases.
These three approaches are what we’ll spend the rest of the chapter
exploring, beginning with the most important: how much we eat.