You Ask, I Answer: Hunger/Metabolism

I've always welcomed feeling hungry as an indication that I'd run out of easily accessible energy and therefore was digging into my accumulated fat.

I mean, how can you lose weight without feeling hungry?

But, I've also read that hunger is associated with a slowing of the metabolic rate which suggests I should NOT welcome the feeling, but instead eat something.

For the sake of argument, suppose I'm disciplined enough not to eat when I feel hungry. Should I eat something or not?

How much does one's BMR vary in response to the sensation of hunger?

I'm 10-20 pounds overweight, (i.e. not obese) and looking for a strategy to maintain my weight or lose a bit.

-- Robert Keyfitz
Washington, DC

Hunger is multi-layered concept.

Firstly, we humans are “special” because our hunger can be motivated both physiologically (there are different theories on this, ranging from low glucose levels to altered body temperature to stomach contractions) and psychologically (reasons not related to the body demanding calories, such as eating to alleviate emotions, eating out of habit, or eating “because it’s time to.”)

Oh, yeah, animals don't know what they're missing -- only we Homosapiens run the risk of scarfing down a bag of chips after a lousy date!

Your question also brings up the issue of weight loss and hunger.

Since these two are closely linked together, it is very important to have a carefully constructed weight loss plan drawn up by a professional – preferably a Registered Dietitians – who is able to implement strategies to make weight loss more manageable.

Telling someone who regularly eats 4,000 calories a day to go down to 1,400 overnight -- as many popular diets recommend -- is a recipe for disaster; yet, because people love quick fixes, they give it a try.

We know what happens. A week later they are about to lose their minds, drop everything, and go back to their established patterns of eating, without having learned any fruitful tactics.

So, should you eat something when you feel hungry?

This really depends on where the hunger is stemming from. Is it physical hunger, or is it masking other underlying emotions (anxiety, depression, boredom, fear, etc?).

Assuming we are talking about physical hunger, the answer is “yes.” The tricky part involves making the right choices.

The key is to choose lower-calorie foods that satiate. Remember that protein, fats, and fiber are the three pillars of satiety.

Note, though, that it is not necessary to have all three of those nutrients present in one food to feel full.

Let me give you an example.

A low-fat, low-protein, fiber-free food like pretzels is a terrible choice, as it takes quite a bit of them (and, thus, quite a bit of calories) to provide a feeling of fullness.

However, something like oatmeal (prepared with some skim milk) provides plenty of fiber and protein. Those 200 calories will leave you fuller for much longer than 200 calories worth of pretzels.

In order to keep metabolism running steadily, I recommend going no more than three hours without eating.

Again, though, this means having small snacks in between meals, not meals in between meals. A large triple chocolate shake from McDonald's may keep you full for several hours, but it also adds 1,160 calories to your day.

Going long periods of time without eating a single morsel of food not only decreases your metabolism, it also makes you more prone to binging.

One of the best weight-loss/maintenance strategies you can implement is to be in control of your food intake.

This means respecting your hunger and satiety, making deliberate choices, and supporting your eating with some structure (i.e.: not letting yourself go more than 3 hours without eating).

You Ask, I Answer: Starvation Mode

I found your site from Google looking for info on the alleged philosophy of your body going into "starvation mode" if it doesn't get enough calories.

I thought I remember seeing a tv special with Dr. Oz de-bunking this.

[He experimented on] a small number of people from Europe [and] found that it's NOT TRUE.

What say you?

-- Laura Lafata
Miami Beach, FL

I am not familiar of any experiment Dr. Oz conducted to debunk this, especially since it is not a myth.

It is a real, documented physiological state.

Here's what I do know in relation to Dr. Oz and "starvation mode."

A quick glance through You On A Diet: The Owner’s Manual for Waist Management (the book he co-authored with Dr. Michael Roizen) reveals the following passage:

“During the Muslim holiday of Ramadan, people eat only after sunset, so they consume all their calories at night. Should they lose weight?

Anecdotal evidence, gathered by doctors watching residents working all-night shifts, indicates that people who eat all their 2,000 daily calories in one meal gain more weight than those who space those calories over three meals.

Why? Because the one-timers are kicking in their starvation mode, making their bodies want to store fat rather than burn it.”

And then there’s this:

“Eat throughout the day so that you're constantly satisfied. The less you eat, the more likely you are to sink into starvation mode and make your body want to store fat.”

So, if anything, Dr. Oz abides by the “starvation mode” concept – as he should!

If we’re talking “across the board numbers,” any meal plan contributing less than 1,200 calories a day puts you in the “starvation mode” category (meaning that our bodies protect fat stores by slowing down the weight-loss process as much as possible).

If these low caloric amounts are continued for a long time, the body continues to resist by saving adipose tissue (fat) and instead sacrificing muscle tissue.

That is NOT good news.

Ultimately, metabolism is compromised (sometimes permanently) and returning to a healthy caloric intake results in weight gain.

This is why it is important to lose weight in a healthy way, not only by getting sufficient nutrients, but also by working with, rather than against, our metabolism.

You Ask, I Answer: Basal Metabolic Rate/Daily Caloric Intake

How can one correctly find their BMR and the calories intake needed for the day?

I have messed up my BMR with my undereating and am in almost malnourished state.

I want to increase my BMR and lose some fat.

From what I understand, maintenance and weight loss is figuring out the equation between calories intake and daily activity.

I just want to know how to estimate a calorie range I should go for and amount of exercise I need to do daily.

I am small - medium frame woman, 130 pounds, and 5' 4", with almost no muscle tone.

-- Mandy (last name unknown)
Halifax, Canada

I’m confused.

You claim to have messed up your basal metabolic rate due to undereating to the point where you are in a “malnourished state”, yet are looking to lose fat?

In any case, to answer your question – yes, weight loss and maintenance comes down to figuring out the net result of calories in (food) minus calories out (metabolism).

Our basal metabolic rate -- the amount of calories we burn off simply by existing -- is ultimately determined by a variety of factors, among them age, genetics, physical activity, dietary paterns, body composition, and hormonal activity.

This last point is especially important. Thyroxin, produced by the thyroid gland, plays a crucial role in metabolism.

In hypothyroidism, very little thyroxin in produced, and BMR is significantly lowered.

If you are cutting calories appropriately and upping physical activity for several weeks and see absolutely no changes, pay a visit to an endocrinologist and have your thyroid gland checked.

Thyroid issues apart, many people appear to forget that some of these factors change with time, age being the most obvious.

This is one reason why, as people age, they find that weight “creeps up on them.”

The 2,500 calories once needed to maintain weight can be too many -- and cause weight gain -- ten years later.

This is where knowing TDEE (total daily energy expenditure) also comes in handy.

TDEE lets you know how many calories you approximately burn each day on top of what your body uses up as a result of standard bodily processes.

So how do you determine all these numbers?

First, calculate your BMR.

You can easily find that out by plugging some basic numbers into Discovery Health’s BMR Calculator.

If you want to get slightly more technical, you can also use the Mifflin-St Jeor formula, developed in 1990, which goes something like this:

Male BMR = 10* (weight in kg) + 6.25* (height in cm) - 5* (Age)+ 5
Female BMR = 10* (weight in kg)+ 6.25* (height in cm) - 5* (Age) -161

NOTE: To convert pounds to kilograms, divide by 2.2 To convert inches to centimeters, multiply times 2.54.

Prior to this, the Harris-Benedict formula (created in 1919) was used. While useful, Mifflin-St.Jeor results in more accurate numbers.

Ok, now: to calculate TDEE multiply your BMR by:

1.2 if you perform little to no physical activity
1.38 if you perform light physical activity a few times a week
1.55 if you perform moderate physical activity at least 3 times a week
1.725 if you perform intense physical activity on a daily basis
1.9 if you perform intense physical activity several times a day or have a very physically demanding job.

Whatever number you get is how many calories you need to maintain your desired body weight.

If you wish to lose -- or gain -- weight, simply subtract – or add – fifteen percent to that figure.

By consuming fifteen percent less calories and increasing your physical activity, you will certainly shed weight.

The fact that you mention having “no muscle tone” is significant, since increasing lean muscle mass is a sure-fire way to speed up metabolism.

This is why weight-bearing exercises are highly recommended -- they help with bone density and metabolism.

Alas, weight loss comes back to the tried and true advice of “eat less, move more.”

You Ask, I Answer: Watching the Clock

Is there any truth behind "Don't eat after 7 p.m." as a weight-loss tip?

Perhaps in the land of unicorns and fairies. In the real world? Not so much.

This myth has been around for ages, and many who have lost weight credit their success to consuming all their calories before a certain time of night.

Let's examine the facts. How do we gain weight? We consume (eat) more energy (calories) than we can burn in a given day. Let's break this down further:

• We all have what is called a basal metabolic rate (BMR)

• Our BMR reflects how rapidly our bodies burn calories while we are in a state of complete rest. (yes, we even burn calories while we sleep!)
  

• If you are looking to lose weight, you want to increase your BMR so your body is able to burn more calories.

• How do you do this? By eating small, frequent meals so your BMR is constantly running, and by performing weight-bearing exercises (whether it’s to bulk up or simply tone your muscles).

• The more muscle mass you have, the higher your BMR.

• When you starve your body, it has no idea when its next meal will be. So, if you go a whole day without eating, your body doesn’t know you are looking to lose weight. It just thinks you are in shortage of food. So, it goes into self-preservation mode and slows everything down in order to store energy, including your BMR.

Our BMR allows us to burn calories throughout the day. Some people only associate this with physical activity, but you are actually burning calories while reading this. Not as many as if you were swimming, hiking, or dancing salsa, but some.

It's simple, really. In the same way that we gain weight by having a great input (calories) than output (burning), we lose weight by doing the exact opposite. So, if you spend the last three hours of the day without having any food, of course you are going to lose weight.

In fact, the people who usually mention the "no eating after x time" rule are those who tend to binge-snack before going to bed. If you find yourself regularly hacing a pint of ice cream while watching Conan and suddenly stop doing so, you are now saving yourself 500 calories. Do that for a week and you'll easily lose approximately one pound of fat!

Similarly, if you are having two donuts for breakfast, a king-size Snickers bar as an AM snack, two slices of pepperoni pizza for lunch, and a can of Coke and a bite-size bag of Cheetos in the afternoon, you will most likely gain weight, even if no food passes your lips after 6 p.m.

Extra calories will become fat no matter what time you consume them.

The key to successful and permanent weight loss is not found in gimmicky solutions given by celebrities, but by you having an understanding of food and your behaviors and habits with it.