Archive for the ‘Nutrition’ Category

The Physiology of Fat Loss

by: Len Kravitz, PhD , Christine Mermier, PhD and Mike Deyhle

From the fat cell to the fat furnace, find out exactly what causes the body to burn fat.

Fat may seem like the enemy of civilized people—especially sedentary ones. Yet we cannot live without it.Fat plays a key role in the structure and flexibility of cell membranes, and it helps regulate the movement of substances through those membranes. Special types of fat, known as eicosanoids, send hormone-like signals that exert intricate control over many bodily systems, mostly those affecting inflammation or immune function.

Of course, the best-known function of fat is as an energy reserve. Fat has more than twice the energy-storage capacity of carbohydrate (9 calories per gram vs. 4 calories per gram). It has been estimated that lean adult men store about 131,000 calories in fat (Horowitz & Klein 2000), enough energy to keep the average person alive for about 65 days.

For fitness professionals, the prime concern arises when the body’s fat-storage function works too well, hoarding unwanted fat that makes people unhealthy and self-conscious about their appearance. Understanding how fat travels through the body can help personal trainers work with clients to reduce excess body fat and improve athletic performance.

The Journey of a Fatty Acid to Muscle

THE ADIPOCYTE

p38 ImageFat resides primarily in designated fat-storage cells called adipocytes. Most adipocytes are just under the skin (subcutaneous fat) and in regions surrounding (and protecting) vital organs (visceral fat). Nearly all fat in adipocytes exists in the form of triacylglycerols (TAGs or triglycerides). Each TAG consists of a backbone (glycerol) with three fatty-acid tails (see Figure 1).

Depending on energy supply and demand, adipocytes can either store fat from the blood or release fat back to the blood. After we eat, when the energy supply is high, the hormone insulin keeps fatty acids inside the adipocytes (Duncan et al. 2007). After a few hours of fasting or (especially) during exercise, insulin levels tend to drop (see Figure 2), while levels of other hormones—such as epinephrine (adrenaline)—increase.

When epinephrine binds to adipocytes, TAG stores go through a process called lipolysis (Duncan et al. 2007), which separates fatty acids from their glycerol backbone. After lipolysis, fatty acids and glycerol can leave the adipocytes and enter the blood.

p39 ImageFatty Acids in the Blood

Because fat does not easily dissolve in water, it needs a carrier protein to keep it evenly suspended in the water-based environment of the blood. The primary protein carrier for fat in the blood is albumin (Holloway et. al. 2008). One albumin protein can carry multiple fatty acids through the blood to muscle cells (Horowitz & Klein 2000). In the very small blood vessels (capillaries) surrounding the muscle, fatty acids can be removed from albumin and taken into the muscle (Holloway et al. 2008).

Fatty Acids Going From the Blood Into Muscle

Fatty acids must cross two barriers to get from the blood into the muscle. The first is the cell lining of the capillary (called the endothelium), and the second is the muscle-cell membrane (known as the sarcolemma). Fatty-acid movement across these barriers was once thought to be extremely rapid and unregulated (Holloway et al. 2008). More recent research has shown that this process is not nearly as fast as once thought and that the presence of special binding proteins is required at the endothelium and sarcolemma for fatty acids to pass through (Holloway et al. 2008). Two proteins that are important for fatty-acid transport into the muscle cells are FAT/CD36 and FABPpm.

Two Fates of Fat Inside Muscle

Once fat is inside the muscle, a molecule called coenzyme A (CoA) is added to the fatty acids (Holloway et al. 2008). CoA is a transport protein that maintains the inward flow of fatty acids entering the muscle and prepares the fatty acid for one of two fates:

  • oxidation (in which electrons are removed from a molecule) to produce energy or
  • storage within the muscle (Holloway et al. 2008; Shaw, Clark & Wagenmakers 2010)

The majority (80%) of fatty acids entering the muscle during exercise are oxidized for energy, while most fatty acids entering the muscle after a meal are repackaged into TAGs and stored in the muscle in lipid droplets (Shaw, Clark & Wagenmakers, 2010). Fatty acids stored in muscle are called intramyocellular triacylglycerols (IMTAGs) or intramuscular fat.

There are two to three times more IMTAGs stored in slow twitch muscle fibers (the slow oxidative fibers) than there are in fast-twitch muscle fibers (Shaw, Clark & Wagenmakers 2010). Shaw and colleagues note that even though this IMTAG supply makes up only a fraction (1%–2%) of the total fat stores within the body, it is of great interest to exercise physiologists because it is a metabolically active fatty-acid substrate especially used during periods of increased energy expenditure, such as endurance exercise.

Fatty Acids Burned for Energy

Fatty acids burned for energy (oxidized) in the muscle can come either directly from the blood or from IMTAG stores. For fatty acids to be oxidized, they must be transported into the cells’ mitochondria (see Figure 3). A mitochondrion is an organelle that functions like a cellular power plant; it processes fatty acids (and other fuels) to create a readily usable energy currency (ATP) in order to meet the energy needs of a muscle cell.

Most fatty acids are transported into the mitochondria via the carnitine shuttle (Holloway et al. 2008), which uses two enzymes and carnitine (an amino acid-like molecule) to do the transporting. One of these enzymes is called carnitine palmitoyltransferase I (CPT1). CPT1 may work with one of the same proteins (FAT/CD36) used to bring fatty acids into the muscle cells from the blood (Holloway et al. 2008). Once inside the mitochondria, fatty acids are broken down through several enzymatic pathways—including beta-oxidation, the tricarboxylic acid (TCA) cycle and the electron transport chain—to produce ATP.

Fatty-Acid Oxidation During a Single Bout of Exercise

At the start of exercise, more blood flows to adipose tissue and muscle (Horowitz & Klein 2000), releasing more fatty acids from adipose tissue and delivering more fatty acids to the muscle.

Exercise intensity has a great impact on fat oxidation.We burn the most fat when exercising at low to moderate intensity—that is, when oxygen consumption is between 25% and 60% of maximum (Horowitz & Klein 2000). At very low exercise intensities (25% VO2max), most of the fatty acids used during exercise come from the blood (Achten & Jeukendrup 2004). As exercise increases to moderate intensity (around 60% of VO2max), most of the fatty acids oxidized appear to come from IMTAG stores (Horowitz & Klein 2000).

p39 ImageAt higher exercise intensities (>70% VO2max), total fat oxidation falls below the levels observed at moderate intensity (Horowitz & Klein 2000). This reduction in fatty-acid oxidation is coupled with an increase in carbohydrate breakdown to meet the energy demands of the exercise (Horowitz & Klein 2000).

We often overemphasize the fatty-acid contribution to calories burned during a bout of exercise. It’s also important to consider recovery from a bout of exercise, as well as training adaptations to repeated bouts, if you’re helping clients meet their fat-loss goals.

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Food Mistakes

By Cynthia Sass

Whether you earn your living working up a sweat, or squeeze in workouts when you can, it’s easy to fall prey to eating errors that unintentionally hold you back from getting the most out of your workouts. Here are five common missteps I see, and how to correct them to reap the rewards of your hard work.

Eating Too Little Fat Despite my recommendations to include good fats at every meal, like avocado, nuts, seeds and coconut oil, some of my clients remain fat phobic, and will scale back, fearing that fat is “fattening.” But the truth is, getting enough fat is a smart strategy for both sports nutrition and weight control, because fat: delays stomach emptying, so you feel fuller longer; increases satiety, to shut off hunger hormones; boosts antioxidant absorption, which in emerging research is related to leanness; and ups metabolic rate, to help you burn more calories. In fact, fat is one of the most vital nutrients in your diet, because it’s a structural part of your cells, which means you can’t heal a cell or construct a new one without enough fat to perform these important jobs. Cutting back too much can result in fatigue, chronic hunger, or a lack of satiety, irritability, depression, a weaker immune system and an increased injury risk. So even if you’re trying to reduce your body fat percentage, don’t be afraid to add almond butter to a smoothie, top your salad with avocado, and sauté your veggies in extra virgin olive oil. Filling the fat gap can be the key to finally seeing results.

Using A Sports Drink When You Really Don’t Need One If you sweat heavily, work out for more than 90 minutes, or exercise in hot, humid conditions, reaching for a sports drink rather than plain water is a smart way to keep hydrated, stay fueled and replace the electrolytes lost in sweat. But if you’re exercising for less than an hour and a half, in a climate-controlled gym, plain water should be fine. The carbs in sports drinks are designed to keep you going when you can’t stop to eat, but if your muscles don’t need the fuel, just one 20 ounce bottle means consuming a surplus 35 grams of sugar, the amount in about 20 gummy bears. And while unsweetened coconut water is a little lower, an 11-ounce jug still contains 15 grams of potentially unneeded carbs.

Not Eating After A Workout Because You’re Afraid To “Eat Back” What You’ve Burned While it’s true that overcompensating for a workout by eating too much can prevent you from shrinking your fat cells, striking the right balance is key. Working out takes a toll on your body, and having the right raw materials to heal and repair the wear and tear is important for seeing results. In other words, it’s not just the training itself, but the healing from the training, that mends muscles, boosts metabolism and makes you more toned and fit. So while a good hard workout isn’t a license to sit down to a big plate of pasta, or eat dessert every night, you should be eating something afterwards, with a goal of delivering the nutrients your body needs to properly recover.

Only Eating Protein Post Workout While protein is a key recovery nutrient, it’s only one piece of the puzzle. In addition to a lean protein source, like a smart phone-sized portion of fish or chicken or a scoop of lentils, you should aim for plenty of produce (to replenish nutrients and supply antioxidants), a healthy fat source (which also helps muscles heal and optimizes circulation), a small serving of a whole grain, like wild rice or quinoa (to replete glycogen, the carbohydrate stored in muscle tissue, which serves as a primary fuel source during exercise) and of course fluid, preferably good old H2O (to rehydrate). If you exercise after work, a great post-workout recovery dinner would be a stir-fry made with chicken, shrimp or organic tofu, along with a variety of colorful veggies, over a small portion of whole grain rice, topped with sliced almonds or black sesame seeds. For a simple aromatic stir-fry sauce, that’s not loaded with sugar, whisk together a few tablespoons of brown rice vinegar, with a splash of fresh squeezed citrus juice (like tangerine or blood orange), and a dash each of fresh grated ginger, minced garlic and crushed red pepper.

 

Doubling Up On Recovery Meals For my pro athlete clients, I highly recommend eating something like an all natural bar or shake within 30 minutes of the end of a game or a tough training session whenever possible, because starting the recovery process within a half hour has been shown to help maximize healing. But employing this strategy if you’re not a pro can wind up working against you. For example, if you munch on a bar or grab a smoothie on the way out of the gym, then go home and eat dinner, you may be in recovery overkill. While it might not register as a meal, a bar with 30 grams of carbohydrate, 5 grams of fat, and 10 grams of protein is like eating a small turkey sandwich with mayo. And a smoothie can be the equivalent of three to four handfuls of fruit, plus a container of yogurt. Downing these “snacks” just an hour or so before eating a regular dinner, can mean giving your body far more than it needs for recovery, which results in feeding your fat cells, rather than shrinking them. If you’re going to be eating a meal with an hour of leaving the gym, skip the bar and shake. And if it’s going to be a little longer, munch on something like almonds, which supply some protein, good fat and nutrients, to tie you over.

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Burpee Equivalents:  Understanding Junk Food in terms of Your Favorite Exercise

by Dr. Jeff Godin, Ph.D., CSCS, & Spartan Coach

Occasionally we slip up with our diets and sneak in some junk calories. When we do, we have to pay the price…In Burpees!  At Spartan Coaching HQ we have been conducting research to quantify energy expenditure during the Burpee exercise.  Here is what we found:

Burpee

 

Calories (kcals)

burpees for 130lb individual

burpees for 180lb individual

1 large French Fries

500

524

349

1 IPA beer

195

204

136

1 Slice of Dominos Peperoni Pizza

260

272

182

1 8 ounce Ted’s Bison Cheesburger

730

765

510

1 scoop of Ben Jerry’s Cookie Dough ice cream

270

283

189

1 12” Roast beef sub from Subway

970

1016

677

1 Cola soft drink

200

210

140

1 Fried Calamari Appetizer

700

733

489

1 Plain Bagel

320

335

223

1 Slice of Cheescake

1000

1048

698

1 Egg McMuffin Sandwich

300

314

210

1 Cadbury Creme Egg

59

62

41

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Food Frauds That Can Wreck Your Diet

Food Fraud: Caesar Salad

Some foods that we think are healthy can be sneaky little diet wreckers. University of Pittsburgh nutritionist Leslie Bonci, MPH, RD, shares a few of these “food frauds,” starting with Caesar salad. Just a small bowl has 300-400 calories and 30 grams of fat, thanks to loads of dressing.

Food Fix: Use only 1 Tbs. dressing and 2 Tbs. tangy, Parmesan cheese.

smoothie

Food Fraud: Fresh Smoothies

That “healthy” berry blend at a smoothie shop can have a whopping 80 grams of sugar, 350 calories or more, little protein, and often no fresh fruit. Fruit “concentrates” are often used instead of fresh fruit. And sorbet, ice cream, and sweeteners can make these no better than a milkshake.

Food Fix: Get the “small” cup. Ask for fresh fruit, low-fat yogurt, milk, or protein powder to blend in protein and good nutrition.

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How Often Should You Eat?

Posted: November 30, 2012 in Fitness, Nutrition
Tags: , ,

Here is a great article that I found on USnews.com.  It discusses the different diets and recommendations for eating frequency.  I am a firm believe in several small meals a day but I can see how that might not work for everyone.  Enjoy the Article!

 

I’m amazed at the emotions that charge the answer to the question of  how many times a day we should be eating. Some people swear by six small  meals, while others stress three square ones. Others argue that two  daily meals, or even one, will suffice. I’ve also met folks who  passionately believe that snacking ensures a successful diet, while others firmly believe that diets can fail on snacks alone.

The  medical literature isn’t much help in these matters. There are studies  clearly demonstrating that frequent eating benefits weight management.  Other studies, however, show that frequent eating leads to caloric  excess.

So how is it possible for there to be so much division and passion,  both in opinion and in evidence, for a singular behavior? How can eating  more frequently be at once fattening and thinning? The answer depends  on both the foods and the individuals involved.

First,  let’s start with whether or not snacking is helpful or harmful to  weight management. Undoubtedly, the answer depends almost entirely on  the snacks. University of Alberta researchers recently found that a  drink and a snack from a vending machine  would provide 15 teaspoons of sugar and 433 calories—roughly the  caloric equivalent of a McDonald’s Quarter Pounder. By those  calculations, people who snack on food from a vending machine may well  find their waistlines challenged.

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Great article about appetite!

Get it. Love it. Keep it.

Do you ever have those days where you are most unsatisfied AFTER you eat? After your meal you find that you are hungry, tired, and craving something sweet?  

Well here are some reasons why  your meals may be leaving a little something to be desired:

 

1. Your food choices: Regardless of calories (in fact forget about counting calories and think about food choices- quality not quantity!) there are foods that fill  you up and foods that leave you wanting more. Fill up on healthy choices (like vegetables, and whole natural foods) and serve yourself a smaller portion of the less nutritious options. Avoid sugar, pop and diet products which are terrible for you and spike your blood glucose levels.

 

2. Your food group balance: if you are lacking in nutrients from a particular area you are more likely to feel fatigued and unsatisfied. Try to eat in a…

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I found this article and recipe by Marni Sumbal and I thought I would share it on my site.  As an endurance athlete I find it very hard to keep from eating everything in site after long workouts.  These habits and this recipe will help not over indulge from the post workout cravings.  Like any recipe you can make modifications to better suit your taste or for what is in your cabinet.  I replaced the tofu with grilled chicken, the wild rice with plain brown rice, and I left out the nutty dip.   Other than that I kept everything the same.  I hope you guys enjoy the tips and feel free to add a comment on how you modified the recipe or if you liked it.

Two strategies that I find very effective for a healthy balance in athletes and fitness enthusiasts are:

  1. Rearrange your plate with similar foods, emphasizing nutrient-dense options
  2. Assess before you act

For the first point — you will see my recipe below which could be titled either “rice bowl with veggies” or, for more nutritional value and nutrient density, “veggie bowl with rice.” I find this very effective for individuals who struggle with portions, have trouble making healthy changes in the diet (to be long-lasting) or struggle with giving up (or eliminating) favorite foods. This makes it much easier to make slow, gradual changes by introducing more healthful items (like veggies) but not completely give-up some of your favorites.

As we all know, habits can be changed. Learning new behaviors doesn’t happen quickly so by making a few swaps you may find yourself gravitating to a new style of eating. I also find this a fantastic tip for all those who have considered an off-limit food list to change body composition. When working with athletes I coach, we say no food is off-limits but we always address how that food makes us feel and how it helps us reach our goals, which leads me to my second point.

This is for those who struggle with second portions, deciding what to have for a meal or snack or struggling with cravings for that after-meal/mid-day sugary treat. This one is simple to suggest but often a struggle at first to implement. Before every meal or snack, ask yourself how that food will make you feel when you eat. You should strive to feel better after you eat than before you started. I find this very useful for individuals who eat a meal but always need that extra something after a meal. I certainly find nothing wrong with a nice small piece of dark chocolate but for those who always have ice cream after dinner or can’t stop after one bowl of cereal or 2 pieces of bread, just ask yourself: “How will this food make me feel when I am done?”

Like I said it sounds very simple but this can make the difference of eating 1/2 cookie and feeling very satisfied with your small portion of a treat after dinner versus having 2 cups of ice cream with chocolate syrup, granola and a few berries on top.

I hope you enjoy my latest creation. It is inspired by the rice bowl at Moe’s Southwest Grill. If these vegetables are not your favorite, feel free to swap in veggies that you enjoy most.

Veggie Bowl with Rice

 

  • Broccoli
  • Corn
  • Green peas
  • Leeks
  • Fresh basil
  • Red bell pepper
  • Green bell pepper
  • Tofu
  • Olive oil
  • Curry powder
  • Nutty dip
  • Wild Rice — cook according to package/box/bag (if seasoning is in separate bag, I recommend using 1/4 of the seasoning rather than the entire package)
  1. In large skillet on low-medium heat, cover bottom of pan with 1-2 Tbsp olive oil.
  2. Add veggies (recommend to steam corn, peas and broccoli for 1:30 in microwave) and tofu and stir occasionally.
  3. When tofu begins to turn golden brown, add sliced leeks (you can use chives or onion) and basil (chopped).
  4. Turn off heat when mixture is soft (around 12-18 minutes depending on heat) and add 1-2 Tbsp nutty dip and stir gently.
  5. Cover and let sit for 1-2 minutes.
  6. In large bowl, add 1 serving of rice (recommend 1/3 – 1/2 cup wild rice to start) to your veggie mixture. Mix and enjoy!

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