By Dr. Mercola
Today's featured video is a lecture by obesity researcher and
neurobiologist Dr. Stephan Guyenet.1
In it, he discusses some helpful and practical tips about the
neurobiological underpinnings of our eating habits that can help
you better understand why you gain weight.
He starts off by noting that the obesity epidemic closely
parallels an increase in daily calorie consumption in the US.
Compared to 1960, Americans eat an average of 363 calories more
per day today. But why do Americans eat so much more
now compared to previous decades?
Guyenet goes on to review some of the alterations to the US
food system that promote overeating, stating that the human
"brain's hardware may not be up to the task of constructively
navigating the modern food environment."
Research does show that what you eat can make a big
difference in how much you eat. As noted by Christy
Matta in a previous article:2
"One study,3
for example, found that obese subjects ate 81 percent more
total calories after eating two meals of instant oatmeal
than they did after eating two meals with the same calories
in the form of a vegetable omelet and fruit."
In a nutshell, research shows that calories gleaned from
bread, refined sugars, and processed foods promote overeating,
whereas calories from whole vegetables, protein, and fiber
decrease hunger.
While Guyenet reviews the role of your brain in all of this,
other researchers have clearly demonstrated how your body's
metabolism is altered by the foods you eat—as well as the impact
of synthetic and toxic chemicals.
Not All Calories Have the Identical Effect
The dogmatic belief that "a calorie is a calorie" has done
much to contribute to the ever-worsening health of the Western
world. It's one of the first things dieticians learn in school,
and it's completely false.
Calories are not created equal, and as just
mentioned, the source of the calories makes all the
difference in the world. Groundbreaking research by
Dr. Robert Lustig shows that calories from fructose are of
particular concern.
According to Dr. Lustig, fructose is "isocaloric but not
isometabolic." What this means is that identical calorie
counts from fructose or glucose, fructose and protein, or
fructose and fat, will cause entirely different metabolic
effects.
However, Dr. Guyenet counters that although this is true at
high levels, most of the human studies have found little
difference in the effects of sugar versus starch at more normal
levels of consumption, as long as excess calories are not
consumed.
The reason for the difference in metabolic effects is
largely because different nutrients provoke different hormonal
responses, and those hormonal responses determine how much fat
your body will accumulate and hold on to.
This is why the idea that you can lose weight by counting
calories simply doesn't work. After fructose, other sugars and
grains are among the most excessively consumed foods that
promotes weight gain and chronic disease.
Another dogmatic belief that simply isn't true is the idea
that obesity is the end result of eating too much and exercising
too little; i.e. consuming more calories than you're expending.
Here, research by the likes of Dr. Richard Johnson clearly
demonstrates that this too is a complete fallacy. Like Dr.
Lustig, Dr. Johnson places most of the blame on excessive
fructose consumption, and his book
The Fat Switch shatters the myth that obesity is the
result of eating too many calories and not exercising enough.
Here again Dr. Guyenet disagrees. He believes that developing
obesity is impossible without consuming more calories than are
expended. If the energy content of your body is increasing, that
means ‘energy in’ has to be increasing, and/or ‘energy out’ has
to be decreasing. It’s just that many things
influence how much is coming in vs. out, for example what type
of food you eat.
Although this may be technically correct the wild card here
that is frequently overlooked is your body’s ability to burn fat
as its primary fuel. Due to insulin and leptin resistance, most
people have impaired enzymes to burn fat which lends credence to
Dr. Lustig’s and Johnson’s assertions.
The Science of Obesity
While the first law of thermodynamics does apply to humans,
in order to actually gain a significant amount of weight, Dr.
Johnson’s research shows that you have to do two things:
- Block your sensation of fullness, and
- Impair your body's ability to burn fat by downregulating
the enzymes responsible for metabolizing fat.
What this means is that in order for you to become severely
overweight you must first become leptin resistant. Leptin is a
hormone that helps you regulate your appetite. When your leptin
levels rise, it signals your body that you’re full, so you’ll
stop eating. Refined sugar (in particular fructose) is
exceptionally effective at causing leptin resistance in animals,
and it’s also very effective at blocking the burning of
fat...
Guyenet also disagrees with this concept. He believes the
most effective way to cause leptin resistance in rodents is a
refined high-fat diet. Please note that these are not the
healthy fats I advocate like coconut oil, avocados, butter and
olive oil, but highly processed and refined industrialized soy,
corn and canola oils.
He also discusses the impact of leptin sensitivity loss in
the featured lecture. He notes that once your brain has lost its
sensitivity to leptin, it will perceive the situation as normal,
and will therefore defend that fat mass.
Another interesting tidbit is that if you’re insulin
resistant and obese, it doesn’t take much fructose to activate
the processes that will keep you fat. Some of Dr. Johnson’s most
recent research shows that the more high-fructose corn syrup you
eat, the more you absorb and the more you metabolize it. Thus,
eating fruits may be more of an issue if you are insulin
resistant, whereas fruit intake is likely safer or even
beneficial if you are lean and healthy. This helps explain the
paradox of how some very fit people can eat a lot of fruit—which
is rich in natural fructose—without gaining any weight.
Toxic Foods and Bad Habits Hamper Proper Metabolic Function
Over the past 60 years or so, a confluence of dramatically
altered foods combined with reduced physical exertion and
increased exposure to toxic chemicals have created what amounts
to a perfect storm. The extensive use of sugar—primarily in the
form of high fructose corn syrup, which is added to virtually
all processed foods—is at the heart of it all. But one also
cannot underestimate the impact of chemistry, and the creation
of truly addictive foods.
If you think about it, it’s quite revealing that, in contrast
to third-world countries, the poorest people in the US
have the highest obesity rates. This seeming
contradiction is, I believe, a clear indication that the problem
stems from the diet itself. Something in the cheapest and most
readily available foods is creating metabolic havoc, and indeed
that’s what studies are finding.
Research into the addictive nature of processed foods reveals
that food companies have perfected the art of creating addictive
foods4
through the masterful use of salt, fat, sugar, and a wide
variety of proprietary flavorings—most of which are far from
natural. As a general rule, "food" equals "live nutrients."
Nutrients, in turn, feed your cells, optimize your health, and
sustain life. Obesity, diabetes, high cholesterol, hypertension,
and heart attacks are all diseases associated with a
processed food diet – a CLEAR indication that it does not
provide the appropriate nutrition for your body.
How to Regain Your Lean Body
So if you are carrying more body fat than your ideal, what's
the answer? I believe there are two primary dietary
recommendations that, if widely implemented, could help you
regain your lean body and reverse our current obesity trend.
This kind of diet will naturally shift your body from burning
sugar to burning fat as its primary fuel, which will
automatically help you shed excess weight, and counteract
disease processes associated with a processed, high-sugar diet:
- Avoid, sugar, refined fructose, grains, and processed
foods
- Eat a healthful diet of whole foods, ideally organic,
and replace the grain carbs with:
- Large amounts of vegetables
- Low-to-moderate amount of high-quality protein
(think organically raised, pastured animals). As a
general guideline, I recommend limiting your protein to
about one gram of protein per kilogram of lean body
mass, or one-half gram of protein per pound of lean body
weight. (If your body fat mass is 20 percent, your
lean mass is 80 percent of your total body weight)
- As much high-quality healthful fat as you want
(saturated and monounsaturated). For optimal health,
most people need upwards of 50-85 percentof
their daily calories in the form of fat
While this may sound excessive, consider that, in
terms of volume, the largest portion of your
plate would be vegetables, since they contain
so few calories. Fat, on the other hand, tends to be
very high in calories. For example, just one tablespoon
of coconut oil is about 130 calories—all of it from
healthful fat. Good sources of fat include coconut and
coconut oil, avocados, butter, nuts, and animal fats.
Also take a high-quality source of animal-based
omega-3 fat, such as krill oil
The Case for Intermittent Fasting
Another strategy that works really well in combination with
this kind of diet is intermittent fasting. In fact, intermittent
fasting, or “scheduled eating,” is one of the most powerful
interventions I know of to shed excess weight, as it effectively
jump starts your body to burn fat instead of sugar as its
primary fuel. There are many different
variations of intermittent fasting, but my personal
recommendation is to fast every day until you reach
your ideal body fat.
You do this by scheduling your eating into a narrow window of
time each day. For example, you could restrict your eating to
the hours of 11am and 7pm. Essentially, you’re just
skipping breakfast and making lunch your first meal of the
day instead. This equates to a daily fasting of 16 hours—twice
the minimum required to deplete your glycogen stores and start
shifting into fat burning mode.
By increasing insulin sensitivity and mitochondrial energy
efficiency, fasting helps slow down disease processes typically
associated with insulin resistance—which includes metabolic
syndrome. Fasting also benefits your body by reducing oxidative
stress, and inducing a cellular stress response (similar to that
induced by exercise) in which your cells up-regulate the
expression of genes that increase their capacity to cope with
stress and resist damage.
Intermittent fasting also has the near-magical side effect of
eliminating sugar and junk food cravings. While most people will
successfully switch over to burning fat after several weeks of
intermittent fasting, it may take up to several months for those
that are seriously insulin/leptin resistant. Their body needs to
learn how to turn on the fat-burning enzymes that allow it to
effectively use fat as its primary fuel. So don’t get
discouraged. Just keep at it. Once you’ve become fat adapted and
are of a normal weight, without high blood pressure, diabetes or
high cholesterol, you really only need to do scheduled eating
occasionally. As long as you maintain your ideal body
weight, you can go back to eating three meals a day if you want
to.
Quit 'Dieting' and Start Living Healthily
If you want to shed excess weight and protect your health, my
most urgent recommendation is to replace processed foods with
homemade meals, made from whole, ideally organic, ingredients.
Remember to replace the grain carbs with vegetables, small
amounts of high quality protein, and plenty of healthful fats.
For step by step instructions and guidance, please see my
optimized nutrition plan.
Intermittent fasting can further boost your weight loss
efforts once you're eating right, as it effectively helps shift
your body into fat-burning mode. Last but not least, exercise
acts in tandem with and boosts the benefits derived from a
proper diet. For maximum benefits, you'll want to make sure to
include high-intensity interval training, which is at the heart
of my Peak Fitness program. To learn more, please see my
previous article: "The
Major Exercise Mistake I Made for Over 30 Years."
Copyright 1997- 2014 Dr. Joseph Mercola. All Rights Reserved.