All posts tagged exercise

Diets Containing 10-20% HFCS / Sugar don’t prevent weight loss.

This was a fun read.

A study published recently (August, 2012) in Nutrition Journal called “The effects of four hypocaloric diets containing different levels of sucrose or high fructose corn syrup on weight loss and related parameters” made some conclusions about sugar consumption and weight loss.

If you don’t know what “hypocaloric” means, it means “low-calorie.” The study took different groups of overweight-to-obese people and placed them on diets containing levels of sugar (sucrose) or HFCS (high fructose corn syrup) in levels of 10-20% of their total caloric intake, and ensured that all groups achieved a caloric deficit of about 300 calories per day. Every group, including the control group, was also put on an exercise program.

And what happened?

Short answer: everyone lost body fat.

Yippie!

I didn’t need to read the article to know that would happen. Come on. That’s just Personal Training 101: calories in vs. calories out–plus the bonus of thermogenetic exercise! Every trainer is taught to sell training on that concept. Burn more than you eat and you lose weight.

“What are you getting at?” you ask.

Well… this isn’t new research. It’s old. Super old. We didn’t need a controlled double-blind study to prove it. Trainers see it every day. Anyone who had ever deliberately lost weight by counting calories know this.

But if you dig deeper and look at the underlying biochemistry of sugar metabolism, it still isn’t news. No one explains it better than Dr. Robert H. Lustig. Sucrose and HFCS are almost identical in composition, and in how they behave in the body.

To be completely fair, HFCS got a very bad reputation for a while. People failed to see that it was pretty much the same as regular table sugar.

The scientists, in an effort to save the reputation of added sweeteners, state:

evidence regarding a potential positive association between sugar sweetened beverage consumption and obesity is inconsistent [43]. Because of the metabolic nature of overweight and obesity and the complexity of the western diet, it is unlikely that a single food or food group is the primary cause. Randomized, clinical feeding trials have shown inconsistent results from testing the effects of added sugar on weight gain. Differences in study instruments and methods, population studied and study design may have contributed to these inconsistent findings.

In other words, science has a very tough time pinning down cause and effect in multi-variable situations. It can’t really. ”Causation” is exceedingly difficult to prove. But correlations are easy to demonstrate. Too easy, sometimes. This is why social context, politics, policy, money, corruption, public opinion, advertising, and everything else should always be factored into the decision-making process. Emotional intuitive (visceral) decisions shouldn’t be overlooked, either. Yes, these things get us into trouble, but so does science.

My favorite quote these days is “100% of all products recalled by the FDA were deemed ‘safe and effective’ by the FDA.” Science can be bullshit. ”Good science” is much rarer in our industry-led scientific data pool.

I have absolutely no argument with what the study concluded:

“In conclusion, similar decreases in weight and indices of adiposity are observed when overweight or obese individuals are subjected to hypocaloric diets with different prescribed levels of sucrose or high fructose corn syrup.” < (AND EXERCISE, you jerks! You left that out!)

At the bottom, I looked for conflicts of interest. Here’s what it said: “JM Rippe has received research funding from the Corn Refiners Association for the present study. The other study authors reported no competing interests.”

Ok… one guy. Big deal. And there were how many scientists?

Here they are:

Joshua Lowndes (jlowndes@rippelifestyle.com})
Diana Kawiecki (Dkawiecki@rippelifestyle.com})
Sabrina Pardo (Spardo@rippelifestyle.com})
Von Nguyen (Vnguyen@rippelifestyle.com})
Kathleen J Melanson (kmelanson@uri.edu})
Zhiping Yu (Zyu@rippelifestyle.com})
James M Rippe (Jrippe@rippelifestyle.com})

Wow! They all WORK FOR Mr. James M. Rippe! No conflict of interest, you say? That’s sweet.

The CORN REFINERS ASSOCIATION paid Mr. Rippe and his associates (or employees) to design a study that teaches us nothing new at all, to make HFCS look less hazardous than it is. I had such a giggle over this I thought I’d point it out to my readers.

HFCS and Sugar consumption at levels of 10-20% of a low-calorie (plus exercise) diet don’t inhibit weight loss when efforts are well-structured and executed. The introduction of HFCS didn’t make us fat, they’d like us to think. Well let me say this: the correlations are staggering.

Correlations are neat little things that help us make general decisions. Correlations should be taken with other correlations and perhaps a dose of intuition. This ads up to lifestyle change.

So keep in mind that the Corn Refiner’s Association is a lobbying group whose sole purpose is to make the public and politicians feel all warm and fuzzy about corn.

Corn. King corn. The CORNerstone of farm policy. The crop that receives the most subsidies (i.e. ‘welfare’). The crop around which our backward policies have enabled the competitive wipe-out of other corn producers. The crop around which so much GMO attention and research is hinging. The crop that is quite impossibly being directed towards “sustainable energy.”

Good old corn, you complicated SOB. I’m so glad these scientists devoted their valuable skills to the promotion of bastardized food production and processing.

1 Comment

by demogirl06 on September 30, 2012 • Permalink

Posted in Food Production and Policy, Nutrition

Tagged causation, corn, correlation, diet, exercise, fat, health, HFCS, lobby, loss, science, sugar, weight

Posted by demogirl06 on September 30, 2012

http://mariamaestevens.com/2012/09/30/diets-containing-10-20-hfcs-sugar-dont-prevent-weight-loss/

Your Hormones: How They Affect Your Weight (part 5: Testosterone)

Hormones are powerful things; they affect everything. Different hormones, of course, directly affect different things. Here’s what you need to know about testosterone.

Testosterone, popularly known as the male sex hormone, is present in both men and women (but in amounts averaging ten times higher in men) as an anabolic (promoting growth) steroid hormone. In men, it is made in large amounts in the testicles; in women, it is made in smaller amounts in the ovaries; and in both men and women, small amounts in the adrenal glands.

Roles:

Testosterone is essential for the development of male reproductive tissues, but has many secondary roles in both men and women: it helps build muscle, burn fat, boost energy, increase strength, increase bone density, lift depression, increase sex drive, and more. In women, higher levels of testosterone are associated with higher levels of assertiveness.

Testosterone can affect fat metabolism:

Testosterone is a muscle building hormone, and muscle helps you burn more calories at rest, while also giving the body a tighter, more compact shape.

Testosterone blocks the effects of lipoprotein lipase, an enzyme that enables the body’s fat cells to store fat. Testosterone also increases fat metabolism by increasing certain key receptors on the fat cell-membrane to release fat. (See article) Through this mechanism, testosterone also increases insulin sensitivity.

*One study suggests that weight loss makes fat men more masculine by preserving testosterone; fat cells synthesize the enzyme aromatase which converts testosterone, the male sex hormone, into estradiol, the female sex hormone (estogen); a decrease in fat cells would lead to a decrease in the synthesis of aromatase, responsible for this phenomenon.

Things that affect testosterone levels in both sexes:

Aging lowers levels of testosterone, along with other factors such as poor diet, alcohol consumption, smoking, caffeine, excess body fat, and stress. It has been suggested that inadequate levels of Vitamin D are associated with decreased levels of testosterone in men.

A nutritious diet, especially one rich in vitamin A, zinc, magnesium, and B6, healthy omega-3s (fish oil, chia seed), and especially amino acids (the building blocks of protein) will promote testosterone production. This is accomplished by eating a variety of fresh vegetables, complete proteins, and healthy fats in the form of nuts, seeds, and olive oil. Watching fat intake is key, as the Standard American high-fat Diet lowers testosterone levels. When seeking complete proteins, watch fat content, as animal-based saturated fats tend to be stored (as fat*, see above), whereas monounsaturated fats (nuts, olives, avocado) and polyunsaturated fats (omega 3s) are used preferentially for fuel.

The incorporation of resistance training–weight bearing exercise–into your fitness program is essential for increasing levels of this slimming hormone. Compound exercises are better than isolated exercises, as they recruit more muscle fibers. Lifting heavier encourages more testosterone production that high-rep, light-weight endurance lifting.

1 Comment

by demogirl06 on December 29, 2011 • Permalink

Posted in Weight Management: Chemistry

Tagged alcohol, amino acid, compound, diet, exercise, fat, levels, omega 3, resistance training, slimming, smoking, stress, testosterone, weight loss

Posted by demogirl06 on December 29, 2011

http://mariamaestevens.com/2011/12/29/your-hormones-how-they-affect-your-weight-part-5-testosterone/

Your Hormones & How They Respond To Exercise

Everything boils down to chemistry. Energy, emotions, fitness…

Interested in which hormones are affected by exercise? Here’s a brief summary:

Growth Hormone (GH) facilitates protein synthesis in the body. as an anabolic agent, GH promotes growth, and cell reproduction and regeneration. If, for example, you have an intense workout, your pituitary gland will produce more GH to accelerate recovery. GH affects are mediated by insulin-like growth factors (IGF-1 and IGF-2), which are synthesized in the liver as a result of GH release during exercise.

Antidiuretic hormone (ADH), also called vasopressin, reduces urinary excretion of water. By conserving water during exercise, it helps prevent dehydration.

Epinephrine and norepinephrine are released by the adrenal medulla as part of the sympathetic response to exercise (the “fight or flight” response). These hormones play two major roles: to increase cardiac output (the amount of blood pumped by the heart) by increasing heart rate during exercise, and to cause glycogenolysis in the liver (breakdown of glycogen), so that more glucose (sugar) can be release into the blood stream. (Note:the body produces more norephinephrine when you eat protein-rich foods).

Aldosterone and cortisol are two main hormones released by the adrenal cortex. Aldosterone limits sodium excretion in the urine so as to maintain electrolyte balance. Cortisal is a glucocorticoid and plays a major role in maintaining blood glucose by release sugar into the bloodstream by the process of gluconeogenesis; cortisol, in other words, increases blood sugar. Cortisol also inhibits the production of serotonin, possibly increasing cravings for carbohydrates (needed to produce serotonin). Due to these factors, elevated levels of cortisol can lead to emotional eating.

Insulin and gluacagon are both secreted by the pancreas, but have opposite effects. Insulin is released in order to remove glucose (sugar) from the blood, and to restore blood sugar levels down to normal. But, when blood sugar is too low, glaucagon is released in order to release free fatty acids from adipose tissue (fat storage sites) so they can be used as fuel instead.

Testosterone and estrogen are the primary male and female sex hormones. Testosterone is responsible for more “masculine” effects in the body, including anabolic (muscle-building) effects. Estrogen is responsible for more “feminine” characteristics and play an important role in bone formation and maintenance. High levels of chronic exercise training have demonstrated decreases in estrogen.

1 Comment

by demogirl06 on November 15, 2011 • Permalink

Posted in Weight Management: Chemistry

Tagged adh, aldersterone, chemistry, cortisol, estrogen, exercise, gh, ghg, gluacagon, glucose, insulin, norepinephrine, testosterone, vasopressin

Posted by demogirl06 on November 15, 2011

http://mariamaestevens.com/2011/11/15/your-hormones-how-they-respond-to-exercise/

Lowering Body Fat: Excess Post-exercise Oxygen Consumption (EPOC)

What do most of us want?

To lose a little weight and tone up.

What that really means is we want a reduction in body fat percentage. After all, “toning up” is really just skimming a little fat off the top of the muscles that already dwell beneath.

And what is the most effective way to reduce body fat?

Burn more calories than you eat.

Sure, you can calorie-restrict. Or, you can do lots of cardio. If you’re really good, you can do both, and sure enough, calorie-by-calorie, you will lose body fat.

But I’m more interested in being time-efficient. And that’s where EPOC–excess post-exercise oxygen consumption–comes in.

In order to maximize the amount of calories burned in a workout, you must maximize the amount of oxygen used during activity. In other words, the harder you’re breathing, the more calories you are burning.

But there’s more to it.

By maximizing the amount of oxygen you use during the day–and not merely in your workouts–you can burn more calories. After your workout, your body needs to use more oxygen to replenish energy supplies, lower tissue temperature, and return the body to a resting state. The harder you work out, the longer it takes to perform these tasks, the more oxygen your body utilizes, the more calories you burn post-exercise.

When people say, “You’re metabolism runs higher after you work out,” they are really referring to this EPOC principle.

The higher the intensity of exercise (the more calories you burn during exercise), the higher the magnitude of EPOC (the more calories you will burn after exercise). Double-whammy.

It’s like taking your car out for a drive. If you drive it hard, red-lining occasionally–burning more gas–and then park it back in the garage, your car will take much longer to cool down its engine (more EPOC). If you simply take it for an easy Sunday drive–being fuel efficient–it will take less time (less EPOC) to cool.

In the goal of body fat reduction, the key is to burn calories, rather than focus on burning fat. Long bouts of cardio are a nice way to improve cardiovascular fitness, but they aren’t the most efficient use of time at the gym, and they certainly don’t contribute as much to high EPOC as other types of training.

And what happens after long bouts of cardio? You deplete glycogen stores. If you’re a cardio-holic, you may have a tendency to always be running on empty, and that paves to way to a binge on carbohydrates later, as your body begs for repleted glycogen. This makes for fit-fat people.

The after-burn of EPOC should not be underestimated. Swap out your 40 minutes of steady state cardio for 20 minutes of work on the bubble between aerobic and anaerobic work, and enjoy the after-burn. Eat immediately after your workout (preferable a source of easily digestible carbohydrates and some protein) within 30 minutes of working out in order to give your body the building blocks it needs to replete glycogen stores and repair muscle tissue, while offsetting a binge later. This, in effect, will lead to more sustainable weight loss.

Less time at the gym; more bang for your buck. More time for other things: like recovery.

2 Comments

by demogirl06 on October 12, 2011 • Permalink

Posted in Exercise Physiology

Tagged aerobic, anearobic, calories, carbs, cardio, consumption, deplete, efficient, epoc, excess, exercise, fat, fuel, glycogen, gym, ogygen, post, replete

Posted by demogirl06 on October 12, 2011

http://mariamaestevens.com/2011/10/12/lowering-body-fat-excess-post-exercise-oxygen-consumption-epoc/

Oxidation: Explaining Free-Radicals, Cell Damage, & Antioxidants

We hear a lot about our foods oxidizing, about free radicals, anti-oxidants, cancer, health problems… these are all terms with which we are familiar, but few laymen can actually explain how it all works.

But first, a crash course in chemistry:

- The human body is comprised of cells. Those cells are made up of molecules. The molecules are made up of atoms.

- Atoms also have a structure: a nucleus (the center), protons (positively charged particles), neutrons (particles with no charge), and electrons (negatively charged particles).

- Electrons like to circle the nucleus in pairs.

Oxidation occurs when oxygen comes in contact with other substances, thereby causing them to lose one or more electrons.

Remember, electrons prefer to travel in pairs; if one is lost, the substance becomes unstable and highly reactive.

The substances are then considered to be free-radicals (that is, atoms, molecules, or ions with unpaired electrons, which are highly reactive and circulate within the body). In doing so, free-radicals, because of their reactivity, can participate in unwanted side reactions resulting in cell damage.

Free-radicals can affect the cell membrane by making it either too vulnerable or too resistant to outside influences. They can also damage the cell’s DNA, which may cause the cell to malfunction or reproduce abnormally. The effect of such chaotic cell damage is now strongly associated with disease.

Unfortunately, the cell damage doesn’t stop at the first cell. The free-radical tends to rob an electron from somewhere else, thereby bastardizing another molecule, which in turn becomes a free-radical in search of another cell to damage.

And yet, not all free-radicals are bad. In fact, some free-radicals are necessary for the regulation of certain biological processes. The body, in turn, produces certain enzymes to control for oxidative damage. But the body isn’t equipped to handle excessive quantities of free-radicals.

Oxidative stress is unchecked free-radical activity. This stress will contribute to overall biological oxidation, which is basically life’s “rusting” process.

So how, practically speaking, are free-radicals created?

We already know free-radicals are a product of oxidation, which is a normal biological process; in fact, the immune system makes them to help destroy bacteria and viruses during an infection.

Many lifestyle factors contribute to the production of free-radicals, including exposure to pollution, chemicals, radiation, and drugs–all factors which have increased as a result of modern lifestyle. Believe it or not, free-radicals also result from exercise (The body uses oxygen to convert fat and sugar into energy. Most of this oxygen combines with hydrogen to produce water, but a fraction of it will end up diverted toward free-radical production.).

Enter antioxidants, which are molecules that behave as free-radical scavengers; that is, they seek out free-radicals and donate the electrons needed to neutralize them.

The body makes antioxidants, but it is also crucial to have dietary sources as well: Vitamin C, Vitamin E, Vitamin A, and the mineral selenium.

Fruits and vegetables are the best sources of antioxidants, especially those famous “super foods” like blueberries, gogi berries, cacao, and blue-green algae.

Though some fruits and vegetables are higher in antioxidants than others, all dietary sources are subject to antioxidant losses due to aging, processing, and their own oxidative processes.

>>>>>>>>>>>>>

Resources:

http://www.biological-oxidation.com/

http://www.associatedcontent.com/article/66098

http://www.nutrabio.com/News/news_free_radicals.htm

1 Comment

by demogirl06 on April 29, 2011 • Permalink

Posted in Biochemistry, Nutrition