Tag Archive: nutrition

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 need to eat before you workout?

So this one is a slippery slope, because we hear two sides of this. I’ve heard not to eat before the gym and I’ve heard to eat before the gym. It’s also a slippery slope because not everyone is looking to get the same thing out of their exercise. Some people want to get jacked and bench press their boyfriends, other people want to run at least 50 miles that day. As you can probably guess, depending on your needs depends on the better answer. So I’m filing this as “Maybe kinda sorta depending” true/false.

Let’s start with my fellow meatheads. When I go to the gym I want to up my lifting and eventually be able to deadlift my boyfriend, then possibly clean and jerk him if we’re attacked in the wilderness (let me pretend gaining strength is everyone’s ultimate goal, mkay?). Anyway, I want anabolism. Yep, anabolism, like “anabolic steroids.” Anabolism = building, catabolism = breaking down. So I want muscle anabolism to be at an all time high. If you skip breakfast and say go to the gym on a 12-16 hour fast, is that good or bad?

Turns out you’ve gotta be smart about it.

This study shows that if you fast, do some gnarly strength training and then down a solid breakfast you have INCREASED anabolism. Other studies found that people who fasted and those who didn’t had the same level of physical performance, at least in strength training.  In fact, you can fast for 3.5 days and have similar levels of isometric strength and anabolism.

But, like other articles before, it’s not all rainbows and sunshine. These studies only studied people who exercised for 90 minutes. I know I have a lot of runner followers that punch out 4 hour runs a few times a week. That’s a bit more than 90 minutes, right? The fasting studies are contraindicated for marathon runners. This study took runners after a 27 hour fast and made them run at 70% maximal O2 uptake, then made them try again 3 hours after a meal – at random. Results? “Fasting caused a 44.7 +/- 5.8% decrease in endurance.”  Other studies have found much the same – marathon, endurance, long distance, etc. runners have a huge decrease in performance if they fasted before exercising.

Depending on what you want from your workout and the length of your workout depends on whether eating beforehand or not will influence your workout. Looking to build strength or working out for less than 90 minutes? Pre-exercise meal isn’t necessary. Is today your long run day? Definitely best to fuel up beforehand.

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

Everything about Iron

What is iron?

Iron is an element that is important for the transfer of oxygen in our blood. It’s also important for regulated cell growth and differentiation. When you have low iron your body has a tougher time of transported oxygen to your muscles, therefore causing fatigue and lowering your immune system. Low iron is one of the causes of anemia.

What is anemia?

Anemia is caused when some issues arises with red blood cells that doesn’t allow them to transport oxygen efficiently. This can be caused by low levels of iron, folate or B12. There are many other causes of anemia that can be spontaneous or genetic, but for the purpose of this article we’ll focus on iron. With iron deficiency anemia the body makes fewer and/or smaller red blood cells. Iron deficiency is the most common cause of anemia.

How do you get iron deficient?

-You lose more iron/red blood cells than your body can make up for

-You are bleeding (this is why “period week” pills in birth control have iron in them)

-You’re not eating enough iron

-Your body is not absorbing the iron

-Your body has an increased need for iron (pregnant/breast feeding)

What are some symptoms of iron deficiency?

When you’re low in iron you will be grumpy, irritable, unable to concentrate, and fatigue easily. Some clinical signs include paleness, brittle nails, your nail beds will be unusually blue, shortness of breath and light headed when standing too fast.

Where can I get iron from?

There are supplements for those who at risk of low iron (heavy menstral periods, vegetarians and vegans, etc). Some natural sources are listed below…

-Red meat

-Egg yolks

-Dark, leafy greens

-Dried fruit

-Iron fortified cereal

-Mollusks

-Turkey or chicken

-Beans, lentils, chick peas

-Liver

-Artichokes

If  you feel that you may be low in iron, consult your family physician. In rare cases there may be underlying causes affecting your bodies ability to absorb iron (Celiacs, Chrohns, or other debilitating diseases).

January 6, 2012 Nutrition Read more >

Insulin Spikes

What is insulin?

Insulin is a hormone that is released whenever glucose is detected in your blood stream. It’s released in order to pull this glucose from your blood stream and bring it into cells to use as energy. Whatever isn’t used is stored in the liver, fat (adipose tissues) and muscle in the form of glucagon. Insulin is considered an “anabolic” hormone, meaning that its release leads to a “build up.” (i.e. – anabolic steroids BUILD muscle, get it?) In insulins case, it helps to bring amino acids (protein) to the muscles, and stores excess glucose as glucagon in the systems mentioned above.

Isn’t that bad?

No way! Too much glucose in the blood is actually toxic. There’s also some research that supports the idea that insulin in the brain promotes learning/cognitive function. Insulin is necessary for our survival.

What is an insulin “spike”?

An insulin “spike” is just when there is an increased level of insulin in your blood stream. There is always insulin in your blood (called “basal insulin”), and this level will rise and fall throughout the day. This can be in response to a meal that is filled with glucose, from exercise, etc.

Glycemic Index

We’ve all seen the commercials about the glycemic index. It’s an index that ranks food based on the amount of simple sugars in them. The higher the glycemic index, the more simple sugars in the blood stream, the more insulin, the more amino acids taken up by muscle (also stops the break down of amino acids in muscle), the more energy in each cell. Sounds great, right?

Why is it considered bad, then?

Just look at what insulin does AFTER it gives energy to the cells. Say you eat something high on the glycemic index while sitting on the couch. Insulin takes the simple sugars to your cells, looking to refuel them…but they’ve been refueled. All you’ve done that day is lounge around and watch Netflix. Next stop? Liver. Fat. Insulin converts the glucose to glucagon and stores that away on your waist line, thighs, hips, etc.

So why have an insulin spike?

Some body builders swear by insulin spikes, and given its ability to give energy to muscles that makes sense. If you just finished a 10 mile run but you have to go to work afterwards for 8 hours it makes total sense to eat something with glucose in it to replenish the energy in each cell, right? (See: protein shakes after workouts, running in the morning and lifting at night, etc.) That’s how it’s used. Since it also prevents amino acids from being broken down (read: proteins/muscle breaking down) it’s great for body builders in muscle gains.

So it’s chill to chug a soda before working out?

It’s not that simple. Think of the adages you read on Tumblr, like “Abs are 80% diet, 20% exercise” or “500 calories of chocolate =/= 500 calories of veggies.” Soda, highly processes carbs, etc. have a lot of other nutrients (or lack of nutrients) in them that can interfere with giving you energy. This is why a lot of people trying to lose weight are told to eat whole grains, veggies, lean protein, etc.

The deal with whole grains/whole wheat/etc.

Why stay away from “white” products, and what does it have to do with insulin? Since many whole grains have more fiber in them they slow down the release of glucose into the blood. They’re also generally complex carbohydrates (complex sugars) which means it takes longer to break them down than simple carbohydrates. This is why they keep you fuller longer than simple sugars. And, in the same vein, since the glucose from them enters your bloodstream slower it causes a gradual, level rise in insulin vs. the quick spike simple sugars are said to give.

Like all food and nutrition, insulin “spikes” can be either a great source of energy or a quick way of gaining fat. Eat a diet mostly composed of unprocessed, whole foods that give you energy and make you feel great. The rest will fall into place!

January 4, 2012 Nutrition Read more >