Metabolism, Calorie Intake, and False Promises Getting Through the Dieting Maze

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This article was edited and updated on December 23, 2021.

The Dieting Maze: Promises, Promises!

There are promises everywhere: Just stand at the grocery line and read the headlines of every magazine cover. The false promises scream at you:

Maybe your mother taught you that all-important maxim: “If it sounds too good to be true, it probably is.” If she did, and you believed her, you can ignore these endless taunts of how you can lose weight and get fit in less than a heartbeat. If she didn’t, maybe you are drawn in, maybe you think, “it might work for me!”

Science is still trying to figure out how our body uses food, as well as how much food and exercise we need...


...we do know that metabolism has a lot to do with what our body does with food.

To think about dieting, you must first think about metabolism.

Metabolism: What is it?

Our body needs food and energy at a cellular level, but no matter what we eat, the cells can't use it in the condition it is in when we eat it. Food goes through several chemical processes after we swallow it — our body will break it down into a state that the cells can use.

Metabolism, then, is the chemical process by which food is converted into food and energy for our cells. If our body doesn't need all of it, it will be stored for use later.

The energy is needed to do everything that you do: not just for exercise class or for your weekend marathon, but also for brushing your teeth or watching television. Those cells are in your brain, your heart, and your lungs, as well as in your muscles.

Metabolism never sleeps; it is working every minute of every day.

There is a close link between nutrients, energy, and metabolism.

Water and Food: Their Link to Metabolism

Here are three reasons why your cells need water:

"German researchers found that drinking 6 cups of cold water a day can raise resting metabolism by about 50 calories daily—enough to shed 5 pounds in a year. The increase may come from the work it takes to heat the water to body temperature. Though the extra calories you burn drinking a single glass don't amount to much, making it a habit can add up to pounds lost with essentially zero additional effort." 3

Every body is different and unique. It doesn't matter if you are young, old, man, woman, thin, heavy-set, tall, short. Food will technically do the same in every person's body, but genetics and gender also play a role.

Here is a list of some foods that are considered to be good for boosting metabolism:

Not only what we eat may make a difference, but how we eat may also help our metabolism. These two paragraphs come from an article in Prevention Magazine:

"Some foods take more work to eat—and therefore burn more calories while you're digesting them. Just the act of chewing foods like fruits, vegetables, whole grains, and lean cuts of meat can increase your calorie burn by up to 30%.

"In a Japanese study, researchers found that women who ate the foods that required the most work had significantly slimmer waistlines than those who ate the softest, easiest-to-eat foods. The fiber and protein in such foods take so much effort to digest that your body doesn't absorb some of their calories." 4

Making use of your Knowledge: First determine your Basal Metabolic Rate

To decide how much food, water, and exercise you need to keep your metabolism fired up, you need to know your basal metabolic rate.

According to Wikipedia, "Basal metabolic rate (BMR) is the amount of energy expended daily by humans and other animals at rest. ... The release, and using, of energy in this state is sufficient only for the functioning of the vital organs, the heart, lungs, nervous system, kidneys, liver, intestine, sex organs, muscles, and skin."

In other words: You must know the minimum number of calories your body needs to survive — to keep your body functioning.

There are internet calculators that will determine your BMR by asking for your height, weight, age, and gender. They can vary considerably. Mine, for instance, tells me that I need anywhere from 991 to 1117 calories a day, depending upon which calculator I use, just to keep my body functioning.

But other things affect the BMR, such as menopause, pregnancy, or even while losing weight.

So, all in all, it's pretty tricky to figure out the minimum number of calories you need to stay alive and healthy, but to not gain weight. The best you can do is use the internet calculators, be as honest as you can about your height and weight, and see what numbers they come up with.

After figuring out your BMR, don't quit — there's more to calculate!

Using our BMR, we know (roughly) how many calories we need to stay alive. But how do we use that knowledge to lose or maintain weight?

To answer that question, you need to know two things beyond knowing your BMR:

Here's an example of how you can calculate whether you have a calorie deficit or surplus on any given day:

To maintain weight: Let's assume that a six-foot 30-year-old male has a BMR of 2000 calories a day. If he eats 2000 calories a day, then there's no problem. Keep the calories going into your body the same as the calories burned, and you will maintain your weight.

To lose weight: Let's stay with the person mentioned above who needs 2000 calories a day just to stay alive. What if he eats 2000 calories that day (the required amount just to keep his body going) but what if he exercises or walks as well? If he burns 500 calories, he will have a 500-calorie deficit. Over time, if he does that every day, he might lose weight.

So we have reached a very basic principle: if you burn more calories than you eat, then you are more likely to lose weight. The accomplishment of that principle is harder to fulfill because there are two unknowns:

How do you calculate the calories you have eaten?

That's a simple question but not quite so simple an answer. It can be done in several ways:

Keep a diary of the foods you eat, so that you can keep track of how many calories you are eating through the day. Develop your own database of the foods you commonly eat — indicate caloric values equivalent to a certain size portion. This just saves time when filling in your diary each day.5

You will learn quickly that eating less will also be useful in keeping the total calories eaten per day at the right level.

It was in 1826 that French physician wrote: Dis-moi ce que tu manges, je te dirai ce que tu es. "Tell me what you eat, and I will tell you what you are."

Keep these simple principles in mind:

The key here is quality plus quantity. We can choose healthy meals, but we can also choose to eat less and exercise more. I know this sounds hard but it is well worth the effort.

How do you calculate calories burned?

There are websites that show you charts of activities and the calories burned, but there is not always an indication of age or gender, weight or height — all of which makes a difference in determining how many calories are burned. I found one that takes into account weight, distance, time, and speed, as well as the incline (steep or flat) or whether or not you are running or walking. But it's difficult to discover one that takes all of these into account. It's even more difficult to find one that goes to other activities besides running and walking.

A very popular item these days is a calorie tracker: I used one called FitBit6, and Nike and Apple make similar devices. I now have an Apple Watch. Before these electronic gadgets, there were the pedometers (just attach to your clothes and it will count how many steps you take); pedometers do not tell you how many calories you have burned, however.

These newer items are worn on your wrist or clipped to your clothes and keep track of the calories you are burning; the totals can be read on the device itself, your computer or your phone and you can also log in your calories eaten. They can easily keep track for you whether or not you are achieving a calorie deficit on any given day.

How accurate are they? In my experience, not terribly accurate, but they do give you a guideline.

Exercise will make your metabolism work more efficiently:

Research shows that we need to do two things in our workouts:

We can't all be Olympic swimmers....make your dreams realistic!

How many times have you — and this applies to either gender — looked at another person and thought, “Wow, I wish I looked like him/her!” Whether we are admiring a model, a bodybuilder, a professional athlete, or someone on the street who just “looks great,” we all fall into the trap of thinking and hoping that we can look like that, too.

What is their secret? we ask ourselves. What do they do? Do they exercise? Lift weights? What do they eat? If I can just do what they do, I’m sure I can look the same. That’s what we dream.

But dreams can turn into nightmares...

There is one little fact — genetics — which we all forget when we start that dream. And because of genetics, we are more likely to be disappointed.

It simply doesn’t work that way. In their book, Body by Science, authors Doug McGuff and John Little discuss this phenomenon — believing that if we want to look like someone else, we just have to do what they do in order to achieve it. “Such claims,” they say, “are made all the time, and, despite their proliferation, they’re wrong.”

This is how it happens. You watch champion swimmers at the Olympics and you observe their appearance. It seems logical to assume that these athletes do something unique that allows them to have that kind of body.

But it is an assumption, McGuff and Little say, that is a “misapplication of observational statistics.”

So what is really happening?

“If you should ever [watch] a swim meet and sit through the whole day’s competition from the initial qualifiers to the finals you would see these ‘swimmer’s bodies’ change dramatically over the course of the day. This speaks to the fact that it isn’t the activity of swimming, per se, that produces this ‘type’ of body; rather, a particular body type has emerged that is best suited for swimming [and they become the champions]. In other words, the genetic cream rises to the top through the selective pressure of competition. Competition, it can be said, is simply accelerated evolution.”

You can want to have the body type of a swimmer, but...can you achieve it?

McGuff and Little finish their discussion about swimmers and their body type by saying: “We draw an inference that is invalid because we are lacking a broader context, which in this instance should have included all of the different body types that also trained [for] the event.” 7

They continue: “It [isn’t] the body type that did well in the activity. It is the genetic endowment that produces the body type. Therefore, if one desires to have the body type of, say, a champion swimmer, the best course is to start by having the same parents as that champion swimmer — rather than his or her training methods.” [my italics]

Avoid the Quick Fixes

Even though we know what the research says about diet and exercise — that permanent weight loss and lifelong fitness are achieved slowly and over time — we are still drawn in by these quick fixes. Just as a reminder, here are some of the bogeymen of the diet and fitness industry:

Better safe than sorry

There is no easy answer. As already stated, lifetime health and fitness occur slowly and steadily over time, and you can’t have one without the other. The diet and fitness regime you choose must become a lifetime commitment. Before embarking on either, follow this checklist:

Be who you are

In the end, there is no need to desire another person’s body type. Instead, you accept the one that you have. The answer is to live well: Exercise, eat good food, learn how to de-stress, have fun, enjoy relationships. Then you will have the best example of your body type imaginable!

See also:

I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.

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  1. These three dots behave exactly like a footnote. Click on them and you will get more information about the topic. ↩︎

  2. In the process of creating energy from the food you eat, your metabolism generates heat. You sweat when you’re overheated to release that heat from your body, and you drink water to replenish the water loss. ↩︎

  3. From a Men's Health Magazine website, an article titled: 15 Easy Ways to Speed up your Metabolism. (See ↩︎

  4. From an article in Prevention Magazine: ↩︎

  5. I know this sounds hard but it is well worth the effort. ↩︎

  6. It fits into a small 'bracelet' which you wear on your wrist. ↩︎

  7. Thanks to authors Doug McGuff and John Little for their book, Body by Science. Published by McGraw-Hill, 2009. ↩︎