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True or False – Eating protein increases your metabolism more than carbohydrates

Posted on March 5, 2013

True.

Could losing weight be as easy as increasing the amount of protein you eat? I do a fair amount of reading when it comes to nutrition and have to say it can be very confusing to try and figure out how much protein we should be taking in. If you read bodybuilding and power lifting magazines, it is common to see recommendations that we should be taking in 1 or 2 grams of protein per pound of body weight. On the other hand, many nutritionists and registered dietitians say that we Americans take in more protein than we need. Whether we get too much or not enough protein, the question of whether protein increases our metabolism more than fats or carbohydrates is an interesting one and one that is getting more attention these days. It turns out that protein actually does increase our metabolism more than fat or carbohydrates do. In a review article published in the Journal of the American College of Nutrition, Halton & Hu (2004) examined previous studies that looked at whether protein increased the thermic effect of food, which they described as being the energy required for digestion, absorption, and disposal of ingested nutrients. It is generally accepted that the thermic effect of protein is 20-30%, compared to 5-10% for carbohydrates, and 0-3% for fat. Halton and Hu concluded that “Convincing evidence exists that protein exerts an increased thermic effect when compared to fat and carbohydrate. The increased amount of energy attributable to this thermic effect is probably too small to have a visible effect on weight loss in the short term, but over periods of months or years, this difference may become significant, both clinically and statistically.” So even though your body will burn more calories breaking down and absorbing protein vs. carbohydrates and fats, it is not a tremendous amount and will likely have little impact on weight in the short term.

Reference:
Halton T, Hu F: The effects of high protein diets on thermogenesis, satiety, and weight loss: A critical review. Journal of the American College of Nutrition (2004), Vol 23, pps. 373-385.

Categories: Myths

True or False – Carbohydrates make you fat

Posted on February 25, 2013

False.

Over the past ten to fifteen years there has been a sharp increase in the number of high protein, low carbohydrate diets being marketed. I believe one of the reasons so many people explore these types of diets is the mistaken belief that carbohydrates make you fat. Carbohydrates are a macronutrient; macronutrients are nutrients we need in larger quantities to help provide energy to cells for normal growth and development. Protein and fats are also macronutrients. Carbohydrates are a very important energy source for our bodies. In fact, many medical and exercise science researchers believe that carbohydrates are the preferred energy source for the brain, and also are important for supplying the energy needs of muscles and other organs in the body. Various organizations recommend that you consume somewhere between 45 and 65% of your daily calories from carbohydrates. So, roughly speaking, it is recommended that the average person consumer more than half of their daily calories in carbohydrates. If your daily caloric intake is about 2,000 calories that would mean you would want to consume roughly 250 grams of carbohydrates per day. One study published in the journal Obesity Research (1996) showed that subjects who ate a carbohydrate rich, low fat diet lost more weight and fat mass than controls that did not change their diets. I find it hard to believe that nutritional experts would recommend we consumer over half our calories in carbohydrates, if carbohydrates in fact made us fat. Additionally, it is often recommended that we consume more complex carbohydrates (whole grain pasta, vegetables) instead of simple carbohydrates (sugars). Now eating too many carbohydrates certainly does have the potential to add extra pounds to your body, just like eating too many fats or proteins. It really comes down to the total number of calories you consume.

Reference:
Siggaard R, Raben A, Astrup A: Weight loss during 12 week’s ad libitum carbohydrate-rich diet in overweight and normal-weight subjects at a Danish work site. Obesity Research (1996), Vol 4, pps. 347-356.

Categories: Myths

True or False – Ulcers are caused by stress

Posted on February 18, 2013

False.

Many of us have a stereotype in our minds of the classic ulcer sufferer. We can picture them- overworked in a high-pressure job, overstressed both at work and at home as well. Incessantly worried, they are bombarded at every side from kids, bosses, clients- the world. They eat antacids like candy and look permanently perplexed as their troubles seem to multiply. If they could just relax and unwind, de-clutter and de-stress their lives, maybe take a stress management course, then the pain in their abdomens would subside, right? As it turns out, that may not be right. In the not-so-distant past, this was the advice given ulcer patients by their physicians. Medical knowledge up until about the early 1980’s suggested that a decrease in blood flow to the stomach during times of anxiety weakened the stomach wall, making it vulnerable to harsh stomach acids. While stress is still thought to create an environment that is conducive to ulcers, it is no longer considered to be the primary culprit.

In the early 1980’s Dr. Robin Warren, a researcher, made a startling discovery. While conducting biopsies of ulcer patients, he found a bacterium which was later named Helicobacter pylori. Warren and his colleague, Dr. Barry Marshall believed that this bacterium, rather than stress, was responsible for the ulcers. Because their claim was such a divergence from conventional belief, it was met with much resistance and skepticism. Unable to convince his peers, Dr. Marshall set out to prove the theory in a radical way. He actually drank the H. Pylori bacteria. Days afterward, he became pale and lethargic and had, indeed, developed an ulcer. Ulcer research thereafter was focused on these bacteria. According to his article in the Journal of Gastroenterology, James Freston (2000) reports that “Helicobacter pylori infection is recognized throughout the world as the most common cause of both duodenal and gastric ulcers.”

Reference:
Freston J: Helicobacter pylori-negative peptic ulcers: frequency and implications for management. Journal of Gastroenterology (2000), Vol 35, pp. 29-32.

Categories: Myths

True or False – Drinking tea has many health benefits?

Posted on February 11, 2013

True.

Millions of people enjoy drinking tea, the second most consumed beverage on the planet. Until recently I had always been a heavy coffee drinker, but I had not given tea a try. Then one evening when I had a sore throat a friend recommended I try some throat-coat tea. I don’t remember exactly what type of tea it was, but it worked and I was hooked. I still drink 2 or 3 cups of coffee in the morning, but instead of continuing to drink coffee when I get to work, I now drink tea. I really love the variety of teas on the market. I’m more of a fruity / flavored tea drinker, the two flavors I have in my office right now are “Wild Berry Zinger” and “Pomegranate Pizzazz”. I spent some time on the internet investigating whether there is health benefits associated with drinking tea and found hundreds of proposed benefits. Supposedly, tea helps with hydration, irritability, headaches, memory, cardiovascular disease, blood pressure, digestion, metabolism, immunity, the flu, cavities, arthritis, Parkinson’s and even bad breath! I then looked for something more scientific on the topic and found an article by Gupta and colleagues (2008) on the beneficial effects of tea published in the International Journal of Pharmacology. These authors sited over 200 references in their paper and discussed how tea has beneficial effects on cancer, skin health, cardiovascular disease, weight loss and even our nerves. The authors stated that “Research conducted in recent years reveals that both black and green tea have very similar beneficial attributes in lowering the risk of many human diseases, including several types of cancer and heart disease.” There are few if any downsides to drinking tea, some tea does contain caffeine, so be careful if you react negatively to caffeine. So, if you currently don’t drink tea, starting to would likely be a simple way to improve your health.

Reference:
Gupta J, Siddique Y, Beg T, Ara G, Afzal M: A review on the beneficial effect of tea polyphenols on human health. International Journal of Pharmacology (2008), Vol 4, pps. 314-338.

Categories: Myths

True or False – Organic food is more nutritious than non-organic food

Posted on February 5, 2013

False.

A few hours before I wrote this section of the book I was in our family’s garden picking raspberries with my 11 year old son. We ended up picking almost two pints worth and probably ate a pint between us as we worked. Following the raspberry harvest we drifted over to the peas and simply smiled at each other as we crunched away, consuming pod and all. Growing healthy food is a topic I am very interested in and rarely if ever do we use chemicals in our garden. I guess I would consider myself an organic gardener. The organic food industry is one that is grown tremendously over the past 5 to 10 years and probably will approach the 50 billion dollar mark this year. Organic farms have traditionally been small scale operations, however, as the interest in organic increases, so does the size of the farms. Generally speaking, organically grown foods are grown without using things like pesticides and herbicides (for plant products) or hormones (for animal products) and some say that organic growing processes have less of a negative impact on the environment.

Many people believe that organically grown food is nutritionally superior to conventionally grown food, but research really doesn’t support that. Dangour and colleagues (2009) published a review article in which they identified 162 articles on organic farming. They then determined that 55 were of satisfactory quality to include in their review. These authors stated that “One broad conclusion to draw from this review is that there is no evidence to support the selection of organically produced foodstuffs over conventionally produced foodstuffs to increase the intake of specific nutrients or nutritionally relevant substances.” There may be many good reasons to grow or purchase organic food; however, to do so because of the belief that they contain more nutrients doesn’t appear to be one of them.

Reference:
Dangour A, Dodhia S, Hayter A, Allen E, Lock K, Uauy R: Nutritional quality of organic foods: a systematic review. American Journal of Clinical Nutrition (2009), Vol 90, pps. 680-685.

Categories: Myths

True or False – Chocolate is good for your health

Posted on January 29, 2013

True.

Are you one of the millions of people who love chocolate? If you are, do you sometimes feel guilty after indulging yourself? If the answer to that is yes, please keep reading! Cocoa and chocolate have been consumed for thousands of years, however, very few of us think about the health benefits associated with chocolate. In fact, it’s only been recently that scientists have started paying attention to the health benefits of chocolate. Chocolate contains compounds called flavonoids, which have been shown to have antioxidant properties, and be very beneficial to health. Research is starting to show that consuming chocolate may help reduce the risk for having a heart attack or stroke, aid in cancer prevention, lower blood pressure, improve insulin sensitivity, decrease blood clotting, and even improve skin health. In fact, there was a conference in 2007 in Milan, Italy where researchers gathered to discuss current research on how chocolate consumption impacts health. Visioli et. al, (2009) published an article in the journal Critical Reviews in Food Science and Nutrition summarizing research presented at the conference. These authors concluded “While the near entirety of experimental data indicate healthful consequences of cocoa intake, the caloric load of chocolate should not be overlooked and its consumption is to be positioned within a balanced and isocaloric diet.” Keep in mind that dark chocolate is much higher in flavonoid content than say milk chocolate which may contain few of these compounds as they can be destroyed during processing. Also be aware of the calories when eating chocolate (there’s always a downside), more isn’t always better. Even a quarter or a half an ounce of dark chocolate per day will likely improve health. Go ahead and indulge yourself, but remember, the darker the chocolate the better, and enjoy in moderation.

Reference:
Visioli F, Bernaert H, Corti R, Ferri C, Heptinstall S, Molinari E, Poli A, Serafini M, Smit H, Vinson J, Violi F, Paoletti R: Chocolate, lifestyle, and health. Critical Reviews in Food Science and Nutrition (2009), Vol 49, pps. 299-312.

Categories: Myths

True or False – If you wait to drink until you are thirsty, you are already dehydrated

Posted on January 22, 2013

False.

I usually get thirsty two or three times during a normal day. If it is a weekend and I am at home working in the yard or the garden, or playing sports with my three children, I might actually experience thirst a half dozen or more times during the day. Should I be afraid that I am chronically dehydrated and that my health is at risk? Most experts are now saying no. This notion of “If you wait to drink until you are thirsty you are already dehydrated” has been around for some time and is something that many people believe. However, there really is very little scientific evidence to support the idea. Heinz Valtin (2002) in an article published in The American Journal of Physiology – Regulatory, Integrative and Comparative Physiology states this notion or fear of being dehydrated if you experience thirst is a myth. He writes that a rise in plasma osmolality (the proportion of materials like glucose and sodium in blood) of 2% can elicit thirst and that a plasma osmolality increase of roughly 5% is when someone would be considered dehydrated.

I spoke with one of my colleagues, Dr. Carl Foster about this. Dr. Foster is a well respected exercise physiologist and a past president of the American College of Sports Medicine. Dr. Foster stated that the idea of already being dehydrated if you got thirsty was a common belief 8 to 10 years ago, and that most experts today think it is perfectly acceptable to let thirst be your guide in regards to drinking fluids. There certainly is nothing wrong with consuming fluids before you are thirsty, but it seems that our society has gotten to the point where the expected norm is to carry a water bottle everywhere you go and be sipping water every 10 or 15 minutes. I’m sure the companies that are making millions keeping us all well hydrated will continue to be in support of that idea.

Reference:
Valtin H: “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8 X 8”? The American Journal of Physiology – Regulatory, Integrative and Comparative Physiology (2002), Vol 283, pp. 993-1004.

Categories: Myths

True or False – When eating celery, you burn more calories than you consume

Posted on January 14, 2013

False.

It is a common belief that eating certain foods results in your body burning more calories than are actually contained in the food itself. These foods are referred to as negative calorie foods. The belief revolves around the fact that when we eat food we do expend some energy breaking down and absorbing that food. This is referred to as the thermal effect of a meal (TEM), the thermal effect of food (TEF), the thermal effect of eating (TEE), or diet induced thermogenesis (DIT). Celery is one of the foods that many claim to be a negative calorie food. Other foods often listed as negative calorie foods include cucumbers, mushrooms, lettuce, onions, zucchini, etc. When you think about it, most of these foods are basically water and fiber. With the number of people who struggle with being overweight now days, this concept of eating negative calorie foods for weight loss purposes has gotten to be very popular. In fact, I did an internet search using the terms “negative calorie foods” and quickly found lots of information on negative calorie diets. I got really excited when I read more information on the negative calorie diet. Apparently, when you follow this diet you can eat all the food you want! While eating all the food you want, you will lose lots of weight. Best of all, if you try this diet you will never be hungry again. I’ll have to admit, I am a bit skeptical. When I read material like that I often think back to my parents telling me the old adage “if it sounds too good to be true it probably is”. I recently came across a book written by Registered Dietician Roberta Larson Duyff for the American Dietetic Association (1999). The author does say that the notion of eating celery as a weight loss aid because you burn more calories than it contains is a myth, and if there is a weight loss benefit it is likely because you are eating the celery in place of higher calorie foods.

Reference:
American Dietetic Association: Food folklore: tales and truths about what we eat. Nutrition Now Series – Tips From the Nutrition Experts (1999), pg 80.

Categories: Myths

True or False – Eating while watching TV increases caloric consumption

Posted on January 7, 2013

True.

Watching TV has become a routine part of most of our lives. Different sources report slightly different statistics on just how much TV we watch. Generally speaking adults tend to watch 2-3 hours of TV a day, with children watching more like 3-4 hours of TV a day. Many people like to eat while watching TV and my wife and I are no different. Like most people we live busy lives, jobs, kids, hobbies, etc., and watching 30 to 60 minutes of television before bed is one way we relax and unwind at night. When we watch TV, we tend to eat. For me, it usually starts with a large bowl of popcorn (we are popcorn addicts)! Then I often make a sandwich, when that’s gone I eat an ice cream cone, I’m somewhat health conscious so I usually have a piece of fruit, and top it off with a large bowl of cereal. Research supports the idea that we tend to eat more calories when we watch TV. Blass and colleagues (2006) did a study and reported that college students ate more pizza (36% more calories) and more macaroni and cheese (71% more calories) during a 30-minute meal while watching TV.

Also, consider the types of food people generally eat while watching TV. We often chose foods like pizza, chips, cookies, ice cream, etc., foods that are calorie dense, but not necessarily nutritionally dense. Very rarely will you find someone sitting down and gorging themselves on broccoli, asparagus, tofu, carrots, spinach, egg whites, and tomatoes while watching TV. What can you do to try and limit the number of calories you eat in front of the TV? If you eat some or all of your meals in front of the TV, turn it off! Try to make healthier choices, eat some cherries instead of the ice cream. Finally, if you must eat things like chips, put a serving or two on a plate and put the bag back in the cupboard. That will help keep you from mindlessly eating until you hit the bottom of the bag.

Reference:
Blass E, Anderson D, Kirkorian H, Pempek T, Price I, Koleini F: On the road to obesity: Television viewing increases intake of high-density foods. Physiology and Behavior (2006), Vol 88, pps. 597-604.

Categories: Myths

True or False – Caffeine improves exercise performance

Posted on January 3, 2013

True.

The majority of people consume beverages that contain caffeine at some point during their day. For many, it’s the two or three cups of coffee they drink early in the morning, for others, it comes in the form of tea or soda. Individuals who purposely consume beverages that contain caffeine often say it gives them a bit of a jolt, helps they wake up or feel more awake, and helps give them energy. Might this translate into improved performance when exercise or physical activity is involved? The overwhelming answer from the research that has been conducted up to this point is yes, caffeine consumption does improve exercise performance. Caffeine is considered an ergogenic aid, something that enhances performance. There have been a tremendous number of studies conducted on caffeine and performance with many of the studies showing that performance is improved by about 10% with the aid of caffeine.

Graham (2001) published an extensive review article on the topic in the journal Sports Medicine, and stated that there is no doubt that caffeine enhances physical performance; he referenced many articles to support the claim. He also stated that he was not aware of any published study that has shown a negative effect of caffeine on performance. Keep in mind, though, that not everyone responds the same to caffeine. Don’t assume you can drink a cup or two of coffee and immediately knock off 3 or 4 minutes from your 5k race time or go out and bike an additional 20 miles. For some, consuming caffeine can result in getting jittery or fidgety and can contribute to increased nervousness or anxiety in others. The International Olympic Committee has set a limit on how much caffeine can be ingested by Olympic athletes. Consuming 1 or 2 cups of coffee likely wouldn’t cause an athlete to be over the limit, but consuming 5 or 6 cups certainly could.

Reference:
Graham T: Caffeine and Exercise: Metabolism, Endurance and Performance. Sports Medicine (2001), Vol 31, pps. 785-807.

Categories: Myths