Yo-Yo Dieting and Your Metabolism

Jul 18, 2016
Healthy Eating

The Ups & Downs of Dieting

Do you feel like you’ve tried every “diet” out there and nothing seems to work? Well if so, you are not alone! While the number varies depending on what source you look at, the Boston Medical Center estimates that approximately 45 million Americans attempt a diet of some sort each year. While media and marketing companies do a great job advertising various “magic pills”, detoxes, and fad diets to make them look like the holy grail of weight loss answers, they often fall short of expectation. We find that we lose weigh, for a while, and then gain it right back, often along with a few unwanted extra pounds. So why is this? What’s happening to your metabolism?

Hungry woman is waiting an order in a restaurant

Below is an explanation as well as some basic guidelines to follow to help you improve your nutrition lifestyle, keep your metabolism happy and healthy, and find balance with your food. (Photo: Livestrong).

Newsflash: All Bodies Are Different

The old thought was that everyone should stick to a 2000 calorie diet (or maybe you’ve heard of sticking to a 1200 calorie diet. Yikes!). But truth be told, we are all different heights, shapes, sizes, and compositions, so it can never be “one size fits all”. We each have what is called a resting metabolic rate (RMR). This value is the number of calories that we each burn during a full 24-hour period at rest; meaning that if we laid on the couch all day, this value is what we need to sustain our body’s basic functions. Here’s the kicker: you should never be eating less than this during a day! This is true even if you are on a “diet”. This value does NOT include: 1) daily activity (e.g. standing up, walking around, breathing, etc.), 2) exercise, or 3) thermic effect of food (your metabolism raises during the digestive process). So often, depending on your activity level, you may need anywhere from 400 or 500 calories to upwards of 1500 or more extra calories per day, beyond that RMR value.Your RMR, plus these three variables is known as your total energy expenditure (TEE). So say you have an RMR of 1500 kcal/day and including those three variables your TEE is 2200 kcal. This is where you would try to have a deficit if you were wanting to lose fat each day by taking in less than 2200 calories AND paying close attention to how you feel. Are you hungry, tired, irritable, etc.? Well then eat more. Another cool piece of information is that the more muscle that you have, the higher your RMR will be due to its high metabolic activity. So what does that mean for you? You get to eat more! By no means am I an advocate of counting calories each day. It’s exhausting and stressful! However, having an idea of what you take in from a couple of days can help you gauge where you are. Then, you can better plan how to incorporate nutrient dense foods into your day to day nutrition to fuel your body, help you meet your goals, and maintain them.


Now we'll take a look at why fad diets create a problem. (Photo Millennial Magazine).

The Truth Behind the Fad Diets

Most fad diets severely restrict calories so you lose weight in the beginning, but then it seems to slow, right? You are likely eating well below what your body needs (your RMR), so your system slows down to adapt to the lack of calories. However, the diet is likely not sustainable forever, and when you go off of it and begin eating normally, you now have a slower metabolism that cannot keep up with the calorie intake that your body used to handle just fine. Thus, the lost weight is back, plus the extra pounds. Probably the biggest takeaway from this article is when you are looking at a diet is could you stay on it forever, and would it fit your lifestyle? If the answer is no, don't do it. What’s more, it shouldn’t be a “diet”. It should just be the way you eat, making small healthy changes over time that becomes part of your day to day. Below are some quick tips to keep in mind when trying to make changes to your nutrition as well as some information on calculating your RMR value.

  • Pick an ultimate goal? What will you gain from meeting this goal? How will it make you feel?
  • Start with a small change and build it into your daily routine. Over time, it won’t seem like a task but rather simply something you do.
  • Set a short term goal each week and try to focus on that rather than the big picture of weight loss. The idea of losing 40 pounds can be daunting, but scaling it back to something like cutting one day of fast food out each week is more doable, and it will contribute to this larger goal.
  • Don't beat yourself up! You shouldn’t try to cut out your favorite foods even if they aren’t the healthiest choice. Allow yourself those treats and then focus the rest of the time on fitting in more nutritious meals.
  • Don’t waste your time or money. Does the “diet” seem too good to be true? It probably is then.
  • Choose general goals to work towards: incorporating fruit, veggies, and lean protein (chicken, fish, etc.) into your menus. For the fruit and veggies, think “taste the rainbow”! Make your plate as colorful as you can.

While there is equipment known as a metabolic cart that actually measures your oxygen and Co2 gas exchange (through a process known as indirect calorimetry) to provide an accurate RMR value, below is a quick equation to give you a rough estimate of this number plus an “activity factor” to give you an estimate of your TEE needs.

The Harris–Benedict equations:

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Activity Factor (RMR plus value below equals your Total Energy Expenditure)

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You don't need the newest and greatest diet to be your newest and greatest self!


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  1. ACSM’s Guidelines for Exercise Testing and Prescription, 9th Ed. Ch.4. 2014
  2. ACSM’s Certification Review, 2nd Ed. 2006. Pg. 176

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