Myths

Can you really lengthen your muscles, or is that a lie?

This comes from the myth of “toning,” which we’ll address some other time, but how many of you have heard this? Said this? The idea is to do exercises that burn fat while making your muscles look “long and lean.” Here’s the deal.

Muscles only grow one way: in diameter.

When muscles grow it is referred to as “hypertrophy.” Hypertrophy literally means an increase in cell size, versus hyperplasia which means an increase in cell number. Muscles cannot undergo hyperplasia, only hypertrophy. So when you’re increasing muscle mass you’re doing so by increasing the size of the individual cells in the muscle.

Additionally, let’s look at the physiology of muscles. Muscles are attached to bone at very specific spots, and are made up of muscles and tendons, plus other contractile proteins. Any medical student will roll their eyes and spew out the long list of origins and insertions, plus various attachments, of every muscle in the body they had to learn in anatomy. Knowing this, how do you increase the length of a muscle without changing the attachment of the muscle? It doesn’t make sense. It would imply that something else has to change too – like the ligaments or tendons it’s attached to would have to shorten in contrast, or the length of the bone would have to change to accommodate this new “length” in muscle to still allow the body to function normally.

Basically, picture a muscle on a bone. Now imagine that muscle growing in length, while nothing else around it changes. Doesn’t really work, does it?

When most medical texts refer to muscle length they’re referring to the tension of the muscle (usually using torque). When adding stretching routines to your workout (yoga, pilates, etc) that increased flexibility is a decrease in the slop of the angle/torque curve, or shifting that entire curve to the right. This is done by stretching the muscle, not by adding length or by somehow making the “bulkiness” of the muscle translate into longer muscles, not fatter muscle cells.

If you’re building muscle you’re building it one way: in diameter. Decreasing the fat that is covering your muscles is the only way for the muscle to appear “long” versus “bulky.”

July 4, 2012 Exercise, Myths Read more >

Do you have to eat every 3-4 hours to increase your metabolism?

This broke my heart, because I am the Queen of eating every few hours. Initially I was really only hungry 3 times a day, but in every magazine I read it said to eat small meals every 3-4 hours. Now I need to eat every few hours or else I feel like I’m starving. But enough about me, let’s talk about how false this is.

This study is my favorite. They took a few obese women and put them on a 1,000 calorie a day diet. Some of the women ate the 1,000 calories in two 500 calorie meals, the other group ate the 1,000 calories split up over the day. What did they find? At the end of 4 weeks the weight loss was the same in the two groups – they lost about the same amount of fat, muscle, etc. They found that the energy expenditure and the diet-induced thermogenesis (what people THINK is an increase in metabolism when you eat multiple times a day) were the same in the two groups. The most interesting part of the study, however, was that after 4 weeks the “nibbling” group had a decrease in sleeping metabolic rate. So the group that ate twice a day had a higher metabolism at night while asleep than the nibbling/grazing group. This study found the exact same thing.

This study takes it a bit further. They looked at it from a weight loss and satiety perspective. Shouldn’t the people who ate multiple times a day be less hungry, and therefore have less Ghrelin, the hormone that stimulates appetite? PYY, the other hormone, does the opposite – it tells you your full. Shouldn’t people who “graze” or “nibble” have more PYY and less Ghrelin during the day? Nope. Both people who ate 3 meals a day and those who ate 3 meals + 3 snacks had the same levels of both hormones. Well, there goes that.

Kinda on the same vein another study looked at how eating 2 meals a day and eating 3 meals a day affected weight loss. Eating 3 meals a day showed an increase in 24h fat oxidation over the 2 meals, but had a lower fat oxidation at breakfast (fat oxidation = breaking down fats in the body into smaller pieces to use for energy). Not surprisingly they found that the people reported feeling more satiated over 24hours with 3 meals a day than 2. However, this differed from the previous study which measured levels of the hormones responsible for these feelings. In this study, they asked the subjects, meaning this finding may be just based on people being used to eating multiple times a day, or the thought of not eating, etc. If you read the conclusion of the study they get all sciencey and brainy on it, I’ll let you make your own decisions.

This study may be where this information of 3-4 hours comes from. It shows that people who nibble/graze have the same level of carbohydrate and fat oxidation during the day. There is no “spike” in metabolism or carb or fat oxidation, it’s pretty much the same all day. People who eat 2/3x a day have peaks, which are compensatory. For example, carbohydrate oxidation is increased after first meal (hearing “breakfast is the most important meal” anyone?) and was decreased over the fasting period (last meal of the night to first meal in the morning). HOWEVER: during the time your carbohydrate oxidation is low, your fat oxidation is HIGH to compensate for energy. So while breakfast proponents tout that your carbohydrate oxidation is low and you need to boost it, they kind of ignore that your fat oxidation is high to compensate. Your body is a well oiled machine guys!

Moral of this story? As long as you eat in a deficit, it doesn’t matter how many times a day you eat. Your metabolism doesn’t “boost” when you eat multiple times a day. Your BMR is your BMR whether you eat 100 calories every 2 hours or a few 500 calorie meals a day. My take? Eat when you’re hungry. It’s a crazy concept, but do it.

July 4, 2012 Metabolism Series, Myths, Nutrition, , Read more >

If I skip a meal or don’t eat for over 12 hours, will my body go into starvation mode?

Oh, starvation mode: how I loathe thee! What does starvation mode even mean? I googled it. Wikipedia says it’s the body responding to long periods of low energy intake. So what is a “long period”? During the fasting study from before we found that it took more than three days of ZERO food for your metabolism to drop 8%. 8%! That means your BMR goes from 1450 calories a day to 1334 calories a day. But we’re not talking about zero food now – we’re talking about less than optimal food.

Let’s go back to the Minnesota Semi-Starvation Study. These guys were fed 50% maintenance for 6 months and their BMR dropped 40%. However, their weight loss never stopped. They hit 5% body fat (rock bottom in men, basically unlivable in females) without breaking stride. At no point and time did their body simply STOP losing weight and “cling” to fat. Yes, their BMR decreased by 40%, but as long as they were eating at 50% maintenance (say maintenance was 2,000, they were eating 1,000. When it dropped to 1900, they ate 900, etc.) they lost weight. It didn’t stall, their body fat didn’t magically increase. Yes, eating below your caloric needs slows down your BMR, but there is never a time where the body magically decides to live off nothing. It’s efficient, but if it were that efficient no one would die of starvation.

So, how much does your BMR decrease? And when? Is there a magic number, like the 1,200 calories a day most would have us believe? This study put women on a mean intake of 490 calories/day. The study is a little iffy because some of the women “cheated” – something I’ll cover in my final post in this series. Anyway, after losing 19kg the BMR of these women dropped 21%. So, if your BMR was 1450, it’s now 1146. The study suggested that this was due to a loss of lean body mass. You know the adage that muscle burns more calories than fat? It’s true. Losing muscle by fasting/lowering your intake below basic needs will eventually cause a loss of muscle and decrease your BMR. The study suggested that lowering your caloric intake enough to lose fat but not muscle would be ideal.

But how do you do that? Cardio?

This study took obese women, fed them 800 calories a day, made them take a spin class that put them at 70% exertion (as in hauling ass) a few times a week and tested their BMR. They became more fit (as in their VOMax increased), but their BMR didn’t really recover. So while it had a short term affect on their metabolism, it really did nothing to stick around.

What about weight training?

This study took a group of people who did cardio plus an 800 calorie diet vs. a group that did strength training and an 800 calorie diet. The cardio group lost more weight, but they lost more lean body mass than the strength training group. In fact, the group that did strength training had an INCREASE in metabolism over the non-strength training group. Their lack of weight loss was attributed to their body burning fat and building muscle, whereas the cardio group just lost weight both in fat and muscle. Moral of this story? Weight training increases muscle, which increases your BMR, which means you lose more fat than muscle, which means your BMR doesn’t tank like it does on just cardio.

Alright, so I strayed off topic a bit with this exercise business and BMR and stuff. Let’s get back to the crux with a great question: Can you fast for a long period of time and lose weight?

Get ready for this: yes. 

Don’t try this at home! A 27 year old, 450+ pound man was put on a fast for an entire year (382 days). Scientists supplemented him with the necessary electrolytes, but otherwise he ate no food. Zero. Zip. Zilch. Nadda. What happened? He got down to 190 pounds. How much of it did he gain back? 15. Now, 5 years after the study, he hovers around 197-ish pounds. On average.

Does that look like he clung to any fat to you?

July 4, 2012 Metabolism Series, Myths, Nutrition, , , Read more >

If you don’t eat, does your body eat your muscle or fat first?

As expected, this is also false. It shouldn’t be a surprise to anyone – it just doesn’t make sense. Off of the top of your head name some important muscles: heart, diaphragm, right? These are necessary to our life. Without them, we don’t function. Why would your body go and target these areas BEFORE going and eating away at fat? After all, stored fat has more energy than muscle (over twice as much, actually) and when was the last time you called someone “starving” because they had only fat and no muscle on them? That’s right, you didn’t.

So why do we continue insisting that our bodies are somehow programmed to preferentially break down our muscles over our energy rich fat? I think Alloran on Fitocracy made the best analogy – “Why tear apart chairs, tables, bed frames, etc. to build a fire when there’s a pile of firewood just outside the door?”

But I wouldn’t call myself Bill Nye with a vagina is I didn’t throw some science at you.

During a two day fast you have a 5 fold increase in Growth Hormone. Growth hormone is what tells the body to conserve protein and therefore muscles. More GH, more protein conservation. GH is a jack of all trades, though, because this badass chick also promotes lipolysis. For those of you who need a Latin reminder, lipo = fat lysis = killing or destroying.  GH kills fat and saves protein.  I told you she was a badass chick.

Growth Hormone isn’t the only big bad chick proving that you burn fat during fasting. Glycerol (released when the body breaks down stored fat) and palmitic acid (also found in fats) are high in the plasma during the first 12-72 hours of fasting. In fact, they double.

But if there’s so much science – and common sense – showing that you don’t lose muscle preferentially, where did it come from? Turns out a few studies showed a decrease in lean body mass (muscle) during a fast. Don’t worry, new science helped to remedy what may have been a misunderstanding. Turns out that majority of the “weight loss” from muscle was a loss of glycogen and water. Glycogen, for you non-bio nerds, is the stored form of glucose. So most of the loss of “mass” from muscle was water and stored glucose. Additionally, these same studies showed that about 14% of the energy from a fast came from protein, whereas 85% came from stored fat.

So no, skipping breakfast, participating in IF, or even lying on the couch all day not eating because you’re sick and lazy won’t cause your body to eat your muscles away. It just doesn’t make sense.

July 4, 2012 Exercise, Metabolism Series, Myths, Nutrition, , , , Read more >

Do you have to “Eat Clean” to lose weight?

One of my major pet peeves is when people tell you the reason you’re not losing weight is because you’re not “eating clean.” What does “eating clean” even mean? You can buy a ton of books on these “lifestyle changes” that involve cutting out sugar, soda, sometimes dairy, sometimes fruit, anything processed, etc. For some people that is hell on earth – you cut out 99% of some peoples diet. I can understand why people tell you this. It’s a lot easier to lose weight when you’re eating cups and cups of spinach (which can be like 20 calories a cup) versus downing a whole 1,200 calorie pizza in one setting. But do you really NEED to eat clean to lose weight?

No. And if someone tells you that, slap them with some science yo.

First, let’s look at the nutrition professor who lost 27 pounds in two months eating just Twinkies, Hostes cakes and other gooey treats. He took a multivitamin and had one protein shake a day, but otherwise he ate Cartman-style meals for 2 months. And lost weight. And improved his cholesterol. His only requirement was to eat 1,800 calories a day or less. Considering his maintenance caloric intake is about 2,500 (according to him) this was enough to cause a serious deficit conducive to losing weight. He. Lost. Weight. Does he recommend this diet to anyone else? No, he doesn’t. He makes an important point though – some people in poor states live like this day in and day out. They only have access to a convenience store and there’s no grocery store for miles. I did an article on this, so you can read it here.

There’s also a marathon runner who sent a PR of 2:34.14 after eating nothing but McDonalds for 30 days. Spoiler alert: he lowered his cholesterol too. (If this freaks you out, google some articles about how Morgan Spurlock’s “Supersize Me” is kinda a total scam)

Now you’re asking, where’s the science? This is just some dude eating crap and losing weight, big deal. Don’t worry. There’s been a TWO YEAR study comparing diets of groups of people by changing their macronutrient intake and showing weight loss over this time. Some people ate only 15% protein, others 40% fat, etc. They wanted to know if the amount of calories you ate were more important than what you ate. Guess what? Calories won. It flew in the face of previous studies that only lasted 6 months or less testing various diets (Zone, Atkins, etc.) on different people. Long term calories are all that matter.

Now, I know what you are thinking. Losing weight =/= health. And you’re right! It doesn’t! These studies don’t take into account building muscle and needing adequate protein, or meeting your daily vitamin nutrients, or any of that fun stuff. However, this series is about metabolism and losing weight, so I’ll assume you all know this.

So no, you don’t have to “eat clean” to lose weight. Calories are king. Do you eat clean because it keeps you fuller longer? Because you genuinely enjoy vegetables and fruits? Is eating cleaning turning out to destroy your social life? Ask yourself these questions before you buy into this idea that you can or cannot eat certain foods in order to lose weight.

July 4, 2012 Metabolism Series, Myths, Nutrition, , Read more >