Which Form of Cardio Is Best For Fat Loss? Comparing HIIT vs. MICT

It’s time we settle this debate. It’s a battle as old as time itself. Is High Intensity Interval Training (HIIT) or Moderate Intensity Continuous Training (MICT) better for fat loss? Luckily, there was a recent meta-analysis published that provides some interesting insight on what the answer might be.

In this post, we will uncover what the met-analysis showed, what it means for you if you do cardio, recommendations on which method to do based on different circumstances and situations, and I’ll finish with putting in a case for cardiovascular training that you may have not considered. For the sake of ease, we’re going to lump HIIT and SIT (Sprint-Interval Training) together because they are similar forms of activity.

So everyone is up to speed, let’s quickly define the two terms. HIIT is typically a series of quick and intense bouts of training where an exercise is repeated either for reps or a certain amount of time while going all out and pushing near 100% with each interval. After the reps are met or time is up, you rest shortly for usually no more than a minute and then you do it again. Think of Crossfit or Tabata workouts for HIIT inspiration.

MICT, on the other hand, is your typical cardio. When people say the word ‘cardio’ you probably think of treadmills, StairMasters, and ellipticals. That’s MICT for the most part. Another part to it is that you don’t adjust the intensity of the exercise. So you stay on level 6 for 20 minutes, for example, without any significant changes.

Before we move on, I want to preface the discussion with this: Cardio is not necessary for fat loss or weight loss. If you’re doing cardio only for these reasons, you’re going to hate your gym life and make yourself miserable. There are a myriad of athletes who don’t do cardio and cut weight just fine such as powerlifters. Of course, if you’re prepping for a bodybuilding show, cardio is a bit more necessary but it’s a short-term endeavor which is more acceptable. Don’t feel pressured to do cardio to lose weight. Refer to my blog post on calories in, calories out to learn how to learn more how fat loss works and how to establish a caloric deficit to really get on track with your goals.

Okay, now that that’s out of the way, here we go. 

Good news is you can really pick whichever form you’d like, because the meta-analysis showed that both methods are equally effective for fat loss. An important point to note here is that the experiment was matched for energy expenditure. This means that the subjects doing HIIT burned the same amount of calories as the people doing MICT¹ during the experiment. Since each method is equally effective, then choosing which method you want to use could be based on things like the time spent on the activity, desired rigor, and personal preference.

On other important note to consider is the degree to which both methods were effective, which wasn’t a lot. Both HIIT and MICT contributed to a body fat reduction of less than 2% on their own. So yes, these methods can be used to elicit fat loss, but probably should not be used on their own. If you’re just doing cardio but not in a net calorie deficit, you won’t experience weight or fat loss. There may be some other benefits you see like improved mood, for example, but body comp. changes may not be seen. That’s why establishing a calorie deficit is nearly essential while incorporating weight training can increase the rate of loss while improving you health further and the way you look if you’re wanting to add muscle. Basically, you can’t just do cardio and not care about our diet or training and expect to shed pounds of fat. Cardio’s effect isn’t that significant!

Moving on.

For time constraints, HIIT is clearly the better option. You can knock out rigorous bouts of training using a seemingly endless variety of exercises in 5-10 minutes and then you’re done.

In addition, if your goal is to build some muscle, this is also a good method, as it may have some crossover effects. Think about it: you’re still likely lifting weights as part of HIIT, so you’re getting in some volume, although the benefit will be likely be minor, if any.

Another touted benefit of HIIT is potential appetite suppression. The meta-analysis pointed to some studies that showed there is a potential suppression of appetite when doing sprints or other forms of HIIT¹ when compared to MICT; although the research is inconclusive because other studies were cited that showed no change, so it’s still up in the air. For you, this is an excellent chance to experiment and see if that works for you or not!

One important note is that HIIT should be VERY hard. In the study, they define HIIT as “80-100% of peak heart rate or aerobic capacity”¹, meaning, this isn’t a bit of huffing and puffing, and then you’re done. HIIT is meant to very intense, so you should be bent over heaving and gasping for breath and possibly on the floor by the end of whatever you did.

It’s not a walk in the park. It’s more like a sprint in the park because a bear is chasing you and is right on your ass. This is a great transition to talk about the cons of HIIT, because there definitely are some!

HIIT is not for everyone. People who never trained before and overweight and obese individuals are perfectly capable of doing some form of HIIT, but it may not be the best option initially because it can come with an increased susceptibility to injury. For an obese person, the quick movements at near-maximal effort, jumping, etc. can be especially burdensome since they carry around a lot of extra weight, damaging their joints and/or bones. For a newbie, it’s a lot of extremely intense work hat they’re not used to, potentially scaring the person away from any form of exercise if you throw them in the deep end at the beginning.

Last con is that cardio is not weight training, and so precautions should be taken if you are weight training to ensure that your HIIT is not interfering with your lifting performance. Some people get very sore from HIIT, which could hinder their lifts. Plan accordingly and give yourself enough time to recover from HIIT if you also plan on lifting weights.

This is not to say no obese person or newbie should never start with HIIT. Some people enjoy the challenge and feeling the burn in their lungs from the get-go and can do it safely; others need to ease into it. Either one is fine, the safety is what’s ultimately important, so you don’t bust your ass trying to do a kettlebell swing.

We can quickly breeze over MICT because it’s bascially warranted whenever HIIT isn’t appropriate as mentioned in the previous paragraphs above.

MICT is the better option if you simply enjoy it more and don’t have time contraints. If you don’t like feeling like you’re about to die (exaggeration) from your cardio, then HIIT probably isn’t up your alley, not to say you can’t work up to getting better a tolerating it.

MICT is also better if you’re dealing with some type of injury. If you have a back injury that prevents you from bending over or causes pain with rotating your torso, MICT has plenty of ways where you can still do cardio without those problems arising.

If you’re overweight, obese, or are new to the gym/cardio, I recommend MICT because it’s a great way to ease into exercise without overloading to dangerous levels of work.

I don’t recommend MICT-or any form of cardio for that matter-if you think that it’s the only way to lose weight, by running on a treadmill for hours. As mentioned before, cardio is not necessary for fat loss. All these reasons for cardio should be supported by the fact you enjoy the training, not because you think cardio is the only way to lose weight.

In short, HIIT and MICT have both been equally shown to influence fat and weight loss (to a small degree). Cardio-however you do it-is simply another tool in your fitness tool belt. You can decide to use it or not. HIIT is good for time constraints, augmenting your lifting, and possibly for appetite suppression. MICT is effective for beginners or overweight and obese people, those concerned that HIIT may interfere with their weight-training sessions, and those who just enjoy getting in some movement without feeling like death.

Have some thoughts on cardio? Comment below and tell me what you think!

References

¹Keating, S. E., Johnson, N. A., Mielke, G. I., and Coombes, J. S. (2017A systematic review and meta‐analysis of interval training versus moderate‐intensity continuous training on body adiposityObesity Reviews18: 943–964. doi: 10.1111/obr.12536.

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Low Fat, Low Carb-Either Still Works: Media Misses The Mark Again

Hey everyone, Michael here. This is the first article on the blog from my friend Dr. Chris Berger. He’s an exercise physiologist and university professor, so he has a lot of good information to share. I hope you enjoy!

Admit it – You’ve had it with the latest studies telling you what to do.  I know I have.  As a doctor of my profession, high-quality data are the lifeblood of what I do.  I carefully structure my research and the classes that I teach on the basis of the best science out there.  But even us PhDs have to roll our eyes occasionally at what gets published and, more importantly, how the media run with it.

Consider, for example, the attention a new study got from the New York Times.  On Tuesday the 20th of February, the Times published a piece titled, “The Key to Weight Loss Is Diet Quality, Not Quantity, a New Study Finds”.  Alright.  Let’s break this down shall we?  First, “weight loss” has no key.  Weight is the product of mass times gravity so, I suppose, you could go into orbit and be happy with your weight absent gravity but… I have some bad news for you – you’d still be FAT!  Next, the notion that something as complicated as body composition (and our very personal concepts of what is ideal) does not have a “key”.  Why do we keep thinking that celebrities have a “secret” or that there is some trick to having a healthy body composition?  Any rational expert in the health sciences will tell you that body composition is dynamic and that obesity is multifactorial.  We owe our percent body fat to a lot of things.  Have we engineered physical activity out of our lives? (Yes)  Are we readily exposed to high-calorie palatable foods?  (Yes)  Have we cut the hell out of PE in schools?  (Ask your kid about that one or…do you not want to interrupt his video game?)  My point is that when you see news of a study that concludes that it’s this – this one thing here everybody – that is making us fat, you need to be critical of the work.

Not surprisingly, this study cited by the Times was praised by an MD – a cardiologist to be exact.  Now don’t get me wrong, I respect physicians.  I just wish that they would respect me.  I have something they don’t have – a thorough understanding of how physical activity impacts body structure and function and the research skills to find out more.  And without them, one draws bone-headed conclusions.  Don’t believe me?  Repeating:  The Times published a piece titled, “The Key to Weight Loss Is Diet Quality, Not Quantity, a New Study Finds”.  Yet what the study ACTUALLY concluded was the following (and I’m copying this verbatim):

In this 12-month weight loss diet study, there was no significant difference in weight change between a healthy low-fat diet vs a healthy low-carbohydrate diet, and neither genotype pattern nor baseline insulin secretion was associated with the dietary effects on weight loss. In the context of these 2 common weight loss diet approaches, neither of the 2 hypothesized predisposing factors was helpful in identifying which diet was better for whom.

But do you even need a PhD or an MD to translate this for you?  THEY FOUND NO DIFFERENCE.

Americans are fat for a lot of reasons but I’d like it to be the case that when we make personal efforts to improve our health, we do so with good information.  We rely on the news media to so inform us.  Instead, what we often have is a rush to headlines and an “endorsement” by somebody who seems credible.  Clickbait.  Bear this in mind for the next time you hear the “breaking news” on something in the health sciences.  Educate yourself on how to read and be critical of studies using the attached guide from the International Food Information Council Foundation and be careful not to jump to conclusions.  There is a lot to know in the health sciences and it’s not likely that one research paper will tell you it all.

Christopher Berger, PhD, ACSM EP-C, CSCS

References:

Gardner CD et al.  Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion: The DIETFITS Randomized Clinical Trial. JAMA. 2018 Feb 20;319(7):667-679.

KMF: Making Macros Fit Your Life

Don’t forget to check out the podcast on itunes!

Check out Kellimichelle.com for her coaching and nutrition programs!

This episode of the Agora Bodkast was produced in collaboration with Kelli Michelle (KMF) and some of her clients. We dive into each of their own personal stories to learn about how they make tracking macros and goal-oriented nutrition part of their everyday lives despite being business owners, executives, night-shift workers, and overall busy people. After listening to this, you can’t say you don’t have time anymore for this stuff! Enjoy, show notes coming soon.

Show Notes:

I Made Some Mistakes On My Last Post, So I Fixed Them Here.

Hey y’all. Finals are done. Classes are out for a little while. I feel good. So good that I’ll be able to get back to writing every week!

Upon reading my last post about aerobic glycolysis, I noticed some issues with the article. There were some things that I either glossed over or need to revise, so this post serves as clarification on some of the hiccups in my last post. Nobody is perfect! Let’s wrap this ish’ up.

First off, I’d like to make the point clear that when you are training, energy systems don’t work like an on/off switch. For example, when you begin high intensity exercise, aerobic glycolysis is working along with the creatine phosphate and lactic acid systems. The difference is that most of your energy is obtained from the latter systems over the former at the beginning of your exercise/work that you’re doing; so energy acquired from aerobic systems will come into play later on as the length of exercise progresses, but the process has begun once you start training.

Next, I made a mistake regarding my explanation of aerobic glycolysis. Glycolysis is only part of the pie known as “Oxidative phosphorylation“. Specifically glycolysis refers to the breakdown of glucose for energy. As a reminder, we can get glucose from carbs or gluconeogenesis such as from lactate and glycerol from fats. This system (oxidative phosphorylation) is the sum of all aerobic reactions and pathways that create ATP; part of which being aerobic glycolysis. Proteins can also be used to produce small bits of ATP.

So during OP, energy may be derived from carbs, protein, and fats! Depending on the availability of nutrients will determine what your body goes for primarily. If you’re full of glucose or glycogen, then your body is going to use that because it’s the quickest and “costs” the least amount of energy to get energy. Your metabolism wants to save all the energy that it can for when it really matters.  Once glycogen stores are depleted, then fats and even proteins will take up a larger role.

Keep in mind that this system takes awhile to produce any energy, so it is not as though you can expect to lose weight just from depleting glycogen stores and relying on fat. You’ll eventually crash because the energy demand just for breathing and moving around could be greater than what can be produced. Simply, get off yo’ butt and move!

So it is a bit more complicated than just carbs and other things being converted into glucose then some magic happens and you have energy. But, that’s the exciting thing about learning! You can learn something new every day!

I hope this clarification of things helped the incomplete picture I painted previously. Maybe I just made it even more complicated. Either way, thanks for reading! Share this article and others to educate someone you know!

 

How Do We Acquire and Use Energy From Food? Part 2

Welcome back to our discussion of energy systems! I appreciate you coming back and your desire to learn! That’s the whole goal of this website: to learn ya’ somethin’! Upon reading a comment from the first post, a reader enlightened me on my neglect to go into detail about what ATP is or what is stands for. So, before I dive into the final energy system, aerobic glycolysis, I’m going to briefly talk about what ATP is! Let’s begin!

ATP Revisted

ATP stands for Adenosine TriPhosphate. This is the molecule our body synthesizes from all these different energy systems in order to make us move in all the ways that we do. Chemically, it is composed of a DNA molecule known as Adenine (in this case, adenosine), ribose, and phosphate groups.

Adenine is one of the four components that create DNA (Only four things known as nucleotides make up your entire DNA sequence! That’s amazing!). Adenine then binds (connects) to ribose, a sugar molecule. Finally, this sugar is bound to a chain of 3 molecules known as phosphate groups.

What makes ATP the OG energy molecule is those phosphate groups. These are known as “High-energy bonds” that, when broken off the ATP molecule, release A TON of energy that our muscles, cells, etc. use to do all the activities that we do.

When a phosphate group is removed from ATP, it becomes ADP (Adenosine DiPhosphate) and AMP (Adenosine MonoPhosphate) when two groups are removed. Here’s a nice visual from Khan Academy¹ to summarize what I mean by molecules, phosphate groups, etc.

Untitled design (8)

Phew. Okay. That covers ATP. Now! Onto the star of the metabolic show, aerobic glycolysis!

Aerobic Glycolysis

Why do I refer to this energy system as the star of the show? This is the system that not only provides the most energy, but it is also in use the most amount of time because typically, we aren’t jumping, sprinting, etc. We only do that for a relatively short period of time (even though it may feel like it never ends).

When we’re just walking, sitting, working, doing normal people stuff, we’re using this energy system. ADDITIONALLY, this is the primary energy system in use when we’re doing light to moderate-intensity exercise for a long period of time.

What’s the reason behind this? Well, for everyday stuff, we’re not in dire need of energy at that very moment like we may be if we’re sprinting away from a bear or angry girlfriend (which are equally dangerous).

Our bodies are built for survival. If it doesn’t need energy ASAP, it’s going to break it down slower but provide more of that energy on a per-cycle basis. What I mean by this is for each “cycle” completed of aerobic glycolysis, we get more energy molecules, meaning more energy for us! Woohoo!

After the lactic acid cycle is depleted/unable to work further, this system kicks in for the remainder of the exercise. Interestingly, long-distance runners can actually notice when their metabolism “switches” to aerobic glycolysis. It’s characterized by fatigue, tiredness, and a feeling of “hitting the wall”. They feel this way because energy isn’t being produced as quickly as we need it.

Also a fun fact, this system is aerobic which means it requires oxygen to start working. Ever notice that you start breathing more the longer you exercise?? You’re taking in that oxygen for a reason. Your body knows when it needs oxygen, and so your brain will tell you to breathe more to take in more oxygen! BOOM!

Why does it take so long to acquire this energy? Aerobic glycolysis relies on fat consumed in the diet or from body fat stores once dietary fat is consumed in order to synthesize glucose and/or ATP. I say ‘and/or’ because when we use fat as energy, it actually breaks into its two components (glycerol backbone and three fatty acid chains, refer to this article on fat for a refresher on the structure of fats).

Glycerol produces a small amount of glucose while the fatty acid chains cannot be converted into glucose; so they have their own metabolic pathway to produce ATP. Creating glucose from sources other than carbohydrate (protein, glycerol, lactate) is known as gluconeogenesis². We actually saw this during the lactic acid cycle! Lactate becomes glucose during the cycle!

Back to the question, fat, as an energy source takes a while because of those damn fatty acid chains. These chains are composed of a lot of carbon atoms that go through a lot (a lot!) of steps to become usable energy. This metabolic pathway is known as Beta-oxidation or fatty acid oxidation.

Why Does This Matter?

Well I’m not going to teach you something if it’s not important! Also, this information will be on the test next Thursday, so make sure you study it.

It’s important because if you do long-duration exercise, you will be using this energy system for most of the time. Additionally, this is the system in use most of the time throughout daily life!

Yeah. So what?

So what? SO WHAT?! This is a sign for you to see that dietary fat is not bad for you. It’s an energy source that is very important for prolonged energy production! Also, if you know that you’re going somewhere without food for a few hours, having fat in a meal prior will help you stay energized. ‘Energized’ does not equal ‘full’ though, keep that in mind. Combat stomach emptiness with fiber and protein!

But, if you need energy for a long time because you won’t get to eat, having some fat from nuts, peanut butter, oils, avocados, seeds, etc. will keep you moving forward! THAT’S why this is important, dammit.

Here is a helpful graph from Precision Nutrition³ to summarize what these last two posts were about. I encourage you to read that linked article too. It’s super informative!

As you can see, ATP stores in the muscle are used up almost instantly, followed by the ATP-PC system (Creatine Phosphate) in purple, then the lactic acid system in green after about 2 minutes. Finally, aerobic glycolysis kicks in for the remainder of the activity at the expense of exercise or activity performance aka “Hitting the wall”.

Image result for energy system use over time

Takeaways

  • ATP is the primary energy molecule made of adenosine, a sugar molecule, and phosphate groups
  • Aerobic glycolysis kicks in after the lactic acid system and continues pumping out energy for the duration of exercise or the activity being performed.
  • Dietary fat and body fat are the primary fuel sources for aerobic glycolysis (Does not mean you can sit on your ass and claim you’re burning body fat. It doesn’t work like that.
  • When used for energy, fat is broken into two components that enter two different metabolic pathways (gluconeogensis for glycerol and beta-oxidation for fatty acids)
  • If you can understand what system is used, you can better prepare meals for exercise or if you’re going to be out for the day!

Do you like posts like this where I explain nutrition science topics?? I love talking about this stuff because I feel that science needs to be communicated to the public more often and in a better way. That’s one purpose of this blog if you couldn’t tell by now! Let me know what you think in the comments! All feedback welcome! Thanks for reading!

References

¹Basic concepts in bioenergetics: phosphoryl group transfers and ATP hydrolysis

²Glucose Can Be Synthesized from Noncarbohydrate Precursors

³All About High Intensity Interval Training (HIIT)

3 Types Of Misinformation + How To Protect Yourself From The BS Part 2

Welcome back! I’m glad you’re interested in checkin’ yourself before you wreck yourself! Let’s jump right into it. A lot of what I discuss here is mostly just personal experience and observations, so it may be a bit more informal than usual. LET’S DO THIS.

If you don’t have the time to read the full article, summary points are at the bottom of the page

Protecting Yourself From The Interweb Snake Oil Salesman

Too Good To Be True?

My personal favorite screening process to do when I come across something questionable is this: Ask yourself if the claim you’re seeing is too good to be true. “Lose 20 pounds in a week, eh? This seems too good to be true.” If an analysis like that goes through your head, It’s very likely that the claim/product doesn’t work and the company or person is just trying to make money to no benefit for you.

 

“All-or-nothing-ers”

Next up is the “All-or-nothing-ers”. What I mean by this is if someone tells you that a certain Thing A delivers Result B 100% of the time or that Result B ALWAYS happens, run away. Almost nothing in any field of science (nutrition and exercise included) is absolute. Even that previous statement wasn’t absolute! This means that there is always an exception to the rules in science.

For example, when someone says “All sugar is bad and sugar will make you fat rah rah rah!”. That’s a statement that falsely encompasses all foods containing sugar as “bad”, whatever that means. If someone can say that an entire nutrient is harmful, they better have some damn good evidence to support it. HINT: They won’t because they don’t know what they’re talking about.

To summarize, words like “always, never, it’s proven that.., believe, every time”. Anything that boxes your choices down to “this or that” is likely a red flag. There’s over 7 billion people on the planet, I can’t think of anything that can be narrowed down to just two options that would categorize everyone in the world properly.

The mark of a credible (and sometimes frustrating) source are key phrases like “may, could, potentially, theory, likely, etc.”. The difference here lies in the degree of certainty in each word. The only thing we can be certain of is our uncertainty! Feel free to use that quote. I said frustrating because we just want a precise answer, but credible, no BS people know that that usually isn’t the case, unfortunately.

If you are unsure of the source, claim, whatever it may be, ask the person pushing the product or idea why this thing is effective. Ask them to provide evidence in the form of peer-reviewed research, the creme-de-la creme of credibility!

Now, not all credible things or people are supported with science 100% of the time. There’s that exception again! It’s your job to make an informed decision on who and what to trust. One thing you could to is to look at past clients or users of a product/service and ask them if they liked it and found it effective. If you’re still unsure, that’s probably a sign from your intuition that it isn’t the right choice for you.

Fear not! That doesn’t mean you should stop your fitness journey! This information should arm you with knowledge to help me wage war on the internet gurus and BS people of the world. That’s what I feel like I’m here to do.

Anyway, back to the goodness.

My Way Or The Highway

This person is closely related to the “all-or-nothing-er” in that they believe the “schools” of nutrition and/or exercise they ascribe to are the only righteous way to train/eat. If you go against them, you are wrong and stupid.

If a person is very close-minded about other ideas and viewpoints, especially when presented evidence that goes against their ideas, run away from them.

Fear Mongering

This one makes me sick. This is where people prey on the lack of knowledge of someone and make them feel like they need a certain product or service in order to be healthy, lose weight, not get cancer, whatever it may be. It’s very sad because not everyone has the time to study nutrition, so it’s up to those who do to provide the correct information. Rather, these assholes exploit that lack of information for financial gain.

If someone is trying to scare you into buying/doing something, it’s likely BS and they just want money.

Cookie Cutter BS

Next on this list of BS-I apologize in advance if this web page smells whenever you open it because of all the BS-is cookie cutter programs! It’s very easy to be a fitness/nutrition coach nowadays, just look good and people will ask how you got there! Often, the person doesn’t actually know, so they just hand out programs based on “what worked for me” or they just put together some quick list of exercises or foods and want $200.

Don’t fall for the trap. If they’re an online coach and it seems like they always have spots open, that likely means that people are dropping them and/or they’re taking on WAY more people than they can adequately coach, lowering the quality of the service.

Proprietary Blends

Another red flag is what is known as a proprietary blend. Typically, you will find this term on supplement labels. A proprietary blend is a special chemical formula that a supplement company will use to create products.

The problem with these blends is that the company can put whatever quantity of ingredient they want without making it clear the amount per serving. For example, a pre-workout may contain caffeine, a common ingredient in this supplement that stimulates and increases focus in many people. If the product is a proprietary blend, they can put either 500mg or 5mg of caffeine. You’ll feel 500mg while the 5mg likely won’t affect you at all. But, they don’t have to tell you how much is contained per serving because of the “proprietary blend”.

My advice? Just don’t buy products that hide behind this label.

To summarize

  • Ask yourself if the product/claim is too good to be true. It often is
  • Proprietary blends for supplements usually mask a gimmick disguised as an exclusive formula.
  • “Always, never, it’s proven that.., believe, every time” BAD
  • “May, could, potentially, theory, likely” GOOD
  • Close-minded people don’t deserve your attention in the fitness world jut as much as they don’t in the political world.
  • Cookie cutter programs and constant open coaching spots are a big red flag for low quality

Did I miss anything? Have you come across misinformation-read:bullshit-in a different form? Share it here and help me fight the crap!

References

¹ Celiac Disease Facts and Figures-University of Chicage Medicine

 

 

Diet Types & Which Work For Weight Loss? Part 2

Welcome back. I missed you. We’re here to finish our discussion on the different types of diets that are out there and to determine which work for weight loss. If you haven’t read part one, we go over what each diet entails and what makes it different from the others. Read it here before reading this so you don’t get lost. Got your favorite reading food ready? Good! Let’s begin.

Low Energy and Very Low Energy Diets

Often, this is the approach many will take when trying to lose weight. They think cutting calories drastically will lead to weight loss. Don’t get me wrong, it absolutely will; however, not all that weight lost will be fat. Up to 25% of the weight lost on these diets can be from muscle aka lean mass1. While many think muscles are only important for bodybuilders, they’re essential for everyone. They help us live our lives injury-free and perform the basic movements that we do without a second thought. Love your muscles. Say thank you by not starving them.

Interestingly, LED & VLED have been able to preserve lean mass on untrained subjects. The research participants were put on a resistance training program and were able to either maintain or increase lean mass2. Keep in mind, these people were untrained and would likely have preserved or built muscle regardless of what happened to them. While interesting, It’s certainly not a reason to try these diets. Being in a chronic (persistent) severe caloric restriction such as LED or VLED can lead to issues arising from low protein intake. Although your calories may consist of mostly protein on these diets, the total amount relative to your body weight matters. On these diets, it’s difficult to acquire that much protein in your diet while staying at such a low amount of calories

Really, one of the only reasons you should be on this diet is if you’re severely obese and you need to drop weight ASAP. Care professionals will often start the patients on a LED or VLED for the first few weeks to begin the loss process. Research shows that this initial restriction actually improves long-term weight loss success3. Over time, however, the drop in calories becomes less aggressive so the patient can slowly increase their metabolism while still dropping weight. They don’t want the patient to be maintaining on the very low calories they started with when they can have them be just as better off on more calories.

Low Fat and Very Low Fat Diets

Low fat diets were all the rage a couple decades ago; but do they actually help with weight loss? Unfortunately, there is little research on VLFD, and none of which cover body composition. These diets are successful in promoting weight loss when intake of fat is reduced from the diet4. Duh. This goes back to what I said in part one. A caloric deficit will usually lead to weight loss.

Although little research has been done on VLFD, there has been some studies that show this diet strategy is difficult to adhere to. When told to consume at most 20% of total calories from fat, subjects were actually consuming around 26-28%, suggesting that it is difficult to stick this diet for varying reasons5. One reason could be that food containing fat is tasty, so people will eat more. Also, lots of foods contain fat, which may make it difficult to reach other macronutrient targets without going over their fat allotment. From this viewpoint, VLFD may not be the best option since you will likely have to go over anyways to satisfy protein and carb intake.

Low Carb and Very Low Carb Diets

There was a recent meta-analysis conducted that did show that LCD diets, especially VLCD, resulted in more fat loss than a normal-level carbohydrate diet6. The findings from this meta-analysis may not be able to be extrapolated (applied to) the general public, as the subjects were obese, and so fat loss was likely regardless of the diet if their calories were being monitored. Still, LCD are very popular and many seem to be able to stick to and enjoy them. I would just say make sure you’re getting in your daily requirement for fiber and fruits and vegetables for the vitamins and minerals if you decide to go low carb. Carbs are still important!

Ketogenic Diets

Here we go. A lot of people think that KD is magic and better than other diets because the decreased level of insulin activity. Carbohydrates are the major trigger for insulin to be secreted. For those who don’t know, insulin acts as a “gatekeeper” between your body’s cells and glucose. Once insulin is secreted, it allows for cells to uptake glucose and provide energy to your body. People think that since carbs are not being consumed as much, that less energy and fat is being stored, hence, relying on body fat for energy; however, when put to the test in the lab, this did not hold to be true.

Research shows that, while a KD can induce weight loss, the net amount is not superior to a normal high-carb, energy-restricted diet7. Does this mean that KD doesn’t work? Absolutely not. It simply means that one is not better than the other. This is good news because it allows people flexibility to select what they want and be confident that if they stick to the diet’s protocols, they should see results!

One interesting advantage of a KD is that it may be appetite suppressing. When subjects were allowed to eat as much as they wanted, unrestricted, the KD group had an average decrease of 294 calories consumed per day8. The reason as to why there was a drop in calories is still unknown. Perhaps because more protein was consumed. Protein helps will fullness, and so may have led to the participants getting full quicker.

High Protein Diets

High protein diets have consistently been shown to be beneficial for weight loss. Protein is the most satiating macronutrient. It helps you feel full, and so you (should) eat less than normal, prompting weight loss. But what constitutes a high protein diet and when is it too much? Some work has shown that consuming about two times the Recommended Dietary Allowance (RDA) is optimal for preserving lean mass while simultaneously reducing fat mass9,10. Anything higher has not shown any benefits for this purpose11. Double the RDA amount is roughly 1.6 grams/kilogram bodyweight (0.7 grams/pound bodyweight).

In Summary

All of these diet strategies can work for losing weight. It is up to you to decide which one you like and what you will stick to. Remember, it’s not the diet that’s going to trigger weight loss, it’s the caloric deficit. That is what matters when we’re concerned with losing weight. Personally, I would not go with LED, VLED, or VLFD. These diets are going to be difficult to stick to, and/or you may not acquire all the necessary nutrients that you need in the proper amounts. I do not have an issue with the other strategies as long as they are being adhered to and you are enjoying the process. Once again, dieting should not be a hellish process if you’re simply trying to lose some weight for an upcoming event or you’re starting a journey to improve your health.

Adopt a healthy, happy relationship with food, and you’ll find that losing weight can be enjoyable and your life does not have to be centered around food! Still have questions? Let me know in the comments below! Thanks for reading! Share this with others who think there are magical diets!

References

1Saris W. Very-low-calorie diets and sustained weight loss. Obes Res. 2001;9 Suppl 4:295S–301S.

2Bryner R, Ullrich I, Sauers J, Donley D, Hornsby G, Kolar M, et al. Effects of resistance vs. aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate. J Am Coll Nutr. 1999;18(2):115–21.

3Nackers L, Ross K, Perri M. The association between rate of initial weight loss and long-term success in obesity treatment: does slow and steady win the race? Int J Behav Med. 2010;17(3):161–7.

4Hooper LAA, Bunn D, Brown T, Summerbell CD, Skeaff CM. Effects of total fat intake on body weight. Cochrane Database Syst Rev. 2015;7(8):CD011834.

5De Souza R, Bray G, Carey V, Hall K, LeBoff M, Loria C, et al. Effects of 4 weight-loss diets differing in fat, protein, and carbohydrate on fat mass, lean mass, visceral adipose tissue, and hepatic fat: results from the POUNDS LOST trial. Am J Clin Nutr. 2012;95(3):614–25.

6Hashimoto Y, Fukuda T, Oyabu C, Tanaka M, Asano M, Yamazaki M, et al. Impact of low-carbohydrate diet on body composition: meta-analysis of randomized controlled studies. Obes Rev. 2016;17(6):499–509.

7Hall K, Chen K, Guo J, Lam Y, Leibel R, Mayer L, et al. Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men. Am J Clin Nutr. 2016;104(2):324–33.

8Johnstone A, Horgan G, Murison S, Bremner D, Lobley G. Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum. Am J Clin Nutr. 2008;87(1):44–55.

9Layman D, Evans E, Erickson D, Seyler J, Weber J, Bagshaw D, et al. A moderate-protein diet produces sustained weight loss and long-term changes in body composition and blood lipids in obese adults. J Nutr. 2009;139(3):514–21.

10Layman D, Evans E, Baum J, Seyler J, Erickson D, Boileau R. Dietary protein and exercise have additive effects on body composition during weight loss in adult women. J Nutr. 2005;135(8):1903–10.

11Pasiakos S, Cao J, Margolis L, Sauter E, Whigham L, McClung J, et al. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial. FASEB J. 2013;27(9):3837–47.