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| Minnesota Sport & Wellness Nutrition, LLC Articles
Can’t Keep the Weight
Off? Here's Why...
(04/04/2011)
Working as a Registered Dietitian, I frequently encounter
clients who swear to following a strict, low-calorie diet and all the while are
still not losing any weight. This rails against the Calories In = Calories Out philosophy that many in the nutrition
and medical professions preach. So that begs the question, what gives? Despite
the perceived mystery, the vast majority of these cases can be explained. Here’s the
low-down on some possible weight loss busters.
Portion Perception
As difficult as it is to suggest to a client they are eating
more than what they’re claiming, this is a very common occurrence. Even small
inaccuracies in tracking your intake can quickly halt weight loss. Consistently
mis-interpreting portion sizes by as little as 10-20% can add up to several
hundred calories over the course of a day.
Sure enough, when people are asked to estimate portions sizes, they most
often under-estimate the true size of what they’re eating. And interestingly, if
a person is hungry, they will under-estimate the portion size to an even
greater degree. Talk about a disaster for weight loss.
There have actually been some great studies that have
demonstrated this. A 1992 New England
Journal of Medicine study examined obese patients that reported following a
low-calorie diet (~1200/day) but yet experienced no weight loss—so-called diet
resistant patients. The investigators measured each diet-resistant patient's
energy expenditure and also assessed their ability to recall what they ate on
previous days. They found that the diet-resistant patients under-reported their
caloric intake by 47% and over-reported their physical activity by 51%. What’s
more, the diet-resistant patients had resting energy expenditures that were
similar to what would be expected, suggesting that their inability to lose
weight had little to do with a “slow metabolism”.
The fact is that when you place a person in a hospital or
metabolic ward to closely measure and restrict their caloric intake, they will
lose weight every time. Some differences exist in regards to the rate
they lose weight, but none-the-less, they DO lose weight. The realities of
real-life settings, however, often make it difficult to precisely measure the
calories we consume and burn.
SOLUTION: Drop the eye-ball method and consider measuring
out your foods for at least a day or two to make sure you are accurately
estimating your portion sizes.
Exercising Too Much
This sounds strange, but there is at least a shred of truth
to this. First, let’s get one thing straight….If you increase your physical
activity and maintain your previous caloric intake, you WILL lose weight
(assuming you were in caloric balance to begin with). To demonstrate this, a
study by Ross et al. (2004) had one group of overweight women reduce their
caloric intake by 500 calories/day through diet changes without any exercise and
another group begin exercising to burn 500 calories/day (~60 minutes) while
keeping their diet the same. Each group was expected to lose 0.5-1.0 pound per week. After 20 weeks, the diet group lost 11.4 pounds
and the exercise group lost 13.4 pounds, indicating that both methods were
equally effective as long as a similar calorie deficit was created.
So how can exercise impede weight loss? Unlike the study
from Ross et al., many people who begin an exercise program are not advised to
closely monitor their diet. In fact, when people are instructed to increase
their physical activity without any mention to their diet, there tends to be a lot
of variation in how much weight they lose. A 2008 study from King et al. verified
this, showing that people who exercised 5 times/week for 12 weeks had weight
changes that ranged from a 32 pound loss to a 4 pound gain. Clearly, not
everyone responds the same to similar amounts of exercise. When the investigators
analyzed the patients by whether they lost weight or not, they found that those
who did NOT lose weight increased their intake by 268 calories/day over the 12
weeks and had higher ratings of hunger. The patients that DID lose weight
decreased their intake by 130 calories/day and did not feel hungrier. Therefore,
it appears that individuals doing similar amounts of exercise will respond
differently in regards to hunger levels and ultimately, whether they increase
their caloric intake.
Something to consider, however, is that your body composition (proportion of fat and muscle) will almost always improve when starting an exercise program, even if you don't lose weight. Ultimately, it may be better to focus more on this instead of just on how your weight changes.
SOLUTION: If you feel hungry on an intense exercise program
and are not losing weight, consider reducing the amount of exercise modestly
and/or focusing more on altering your caloric balance through dietary
changes. Remember to track other outcomes besides weight, like waist circumference and body composition.
Choosing the Wrong
Types of Food
While the above sections highlight the importance of caloric
balance for weight loss, there is something to be said for the influence of
food choices. In general, reduced calorie diets that differ based on the
percentage of calories from fat, protein, and carbohydrate typically do not
show significant differences in weight loss after 1-2 years. However, data from
the National Weight Control Registry (NWCR) indicates that a low-fat approach
may be best for long-term weight loss. The NWCR collects information on
individuals—currently over 5,000—who have lost a significant amount of weight
and have kept it off. The average weight loss reported by NWCR participants is
65 pounds and the average duration of weight maintenance is 5.5 years. Of note,
80% report eating less than 30% of calories from fat and only 11% report using
a low-carbohydrate diet (Shick et al., 1998).
Also, those ingesting less than 24% of calories as carbohydrate maintained
their weight loss for less time and were less physically active.
SOLUTION: Avoid diet changes you cannot envision yourself maintaining for years
to come. A low-fat approach may be superior in the long-term because it may
allow you to consume a larger volume of food in comparison to a diet based on higher-fat
foods. Remember, though, that a low-fat diet high in calories will still lead to
weight gain!
Metabolic and Hormonal
Conditions
While the majority of poor weight loss can be explained by
the issues discussed, several conditions can make it more difficult for someone
to lose weight. Thyroid dysfunction and polycystic ovarian syndrome (PCOS) are
examples of conditions that can negatively alter metabolism and energy
expenditure. If you continually struggle to keep off weight despite trying some
the remedies mentioned, consider contacting your physician or other credentialed
health professional to be evaluated.
References:
-King et al. (2008). Individual variability following 12
weeks of supervised exercise: identification and characterization of
compensation for exercise-induced weight loss: Exercise, compensatory responses
and energy balance. International Journal of Obesity, 32, 177-184
-Lichtman et al. (1992). Discrepancy between self-reported
and actual caloric intake and exercise in obese subjects. New England Journal of Medicine, 327 (27),
1893-1898
-Ross
et al. (2004). Exercise-induced reduction in obesity and insulin resistance in
women: a randomized controlled trial. Obesity
Research, 12 (5), 789-798
-Shick et al. (1998). Persons successful at long-term
weight loss and maintenance continue to consume a low-energy, low-fat diet. Journal
of the American Dietetic Association, 98, 4, 408-413
Kill the Carbs? (12/20/2010)
A recent story in the LA Times (see link below) provided some seemingly convincing arguments that carbohydrates (carbs) are dreadful for most Americans’ health. For sure, statements such as, “Americans can also blame high-carb diets for why the population has gotten fatter over the last 30 years…” seem to point the finger squarely on the once highly regarded carbs (remember the food pyramid built on grains?). But should most of us be following a low-carb diet? Do these claims actually hold merit? Let’s take a look. The article—and others like it—do make some valid arguments. There is little question that Americans are now eating more carbs (especially refined versions and added sugars) than we did in the past. At least some of the blame for this should fall on the governing health bodies that for years advocated low-fat diets without making mention of the quality of foods that should replace the fats. What’s more, we know that particular groups of people—such as overweight and obese women—do a particularly poor job at managing large amounts of refined carbs. And as the LA Times article points out, some studies show that low-carb diets may improve certain measures of health more than low-fat diets, such as lowering blood triglycerides (fats) and raising HDL cholesterol more. What the article fails to mention, however, is that Americans are eating almost more of everything, including added fats. Both fats and carbs become harmful when we eat calories in excess and placing blame on one or the other is too simplistic. And even though the studies that show low-carb diets improve blood fats are interesting, they usually do not measure what we are most interested in—the development of diseases and death. Science has been fooled in the past by relying on changes in risk markers to evaluate treatments. Case in point, trials of new HDL cholesterol raising drugs during the mid-2000s actually showed patients taking the drugs were more likely to die than those taking a placebo pill. Remember, HDL is the so-called “good” cholesterol and we would usually expect to see benefits from raising it. So what do studies on low-carb diets that measure disease and death tell us? Well for starters, there are very few of these studies because of the time and expense needed to complete them. In the September 2010 issue of the journal Annals of Internal Medicine, a study looked at how low-carb eating patterns influenced the likelihood of death in 130,000 men and women over several decades. The authors used food questionnaires to see to what degree each person’s diet was low-carb and to what degree it was plant-based and animal-based. Overall, they found that a low-carb eating pattern had little influence on death, but when separated by the main source of protein and fat (animal vs. plant), those eating a more plant-based low-carb diet were better off than those eating an animal-based low-carb diet. Of note, this was not an intervention study, meaning the participants did not change anything in their diets. There has never been a long-term, large study that has changed people’s diets to a low-carb eating pattern to see how it would influence the development of heart disease, diabetes, or death. So what, then, do we do with this information? Just like anything else, opinions will vary among health professionals. If you do decide to follow a low-carb eating plan, remember that the claims often made are low in the type of evidence we like to make recommendations off of. Perhaps the old saying, “Proceed at Your Own Risk” is fitting of the low-carb mantra. http://www.latimes.com/health/la-he-carbs-20101220,0,5464425.story?page=2 References: -Fung et al. (2010). Low-carbohydrate diets and all-cause and cause-specific mortality. Annals of Internal Medicine, 153 (5), 289-298
Do Athletes Need Antioxidant Supplements? (8/27/2010)
Antioxidant has become a buzz word in nutrition, not only for health, but also in sport. A trip to your grocery store nowadays reveals a plethora of products promoting antioxidants in everything from granola bars to breakfast cereals. Sport supplements claim antioxidants will do everything from help you train harder to recover quicker from an intense workout. What exactly, though, is an antioxidant? And do athletes really need to be supplementing their diets with these nutrients?
What is an antioxidant?
In any human being, reactions required to sustain life produce molecules that have unpaired electrons. These molecules, known as reactive oxygen species (ROS) or free radicals, are very unstable and can react with other molecules in the body. Lipids, proteins, and DNA in the body can all be damaged by these ROS, and excessive damage can contribute to everything from type 2 diabetes to premature aging. This is the point at which antioxidants enter the picture. The unique chemistry of antioxidants allow them to gobble up unpaired electrons and effectively prevent them from damaging the body’s cells, DNA, and proteins.
Some nutrients in the diet are antioxidants themselves, such as vitamin C, vitamin E, carotenoids, and polyphenols, while other nutrients are a part of proteins in the body that act as antioxidants. For example, the trace mineral selenium is required for the antioxidant glutathione peroxidase to work properly. Copper and zinc are also a part of antioxidant proteins that our bodies make. Antioxidants in the diet are most abundantly found in fruits, vegetables, nuts, legumes, spices, and herbs.
Do athletes need antioxidant supplements?
ROS are thought to be at least partially responsible for the muscle damage experienced from intense exercise. During repeated muscle contraction, excessive production of ROS can overwhelm the body’s antioxidant defenses, causing an imbalance known as oxidative stress. Indeed, studies do show that athletes tend to produce more ROS than the average couch potato.
So additional antioxidants are needed, right? Well, it’s not quite that simple. The body’s natural antioxidant defense systems—like superoxide dismutase—are increased in response to exercise training. What’s more, several studies have shown that ROS are partly responsible for the adaptations we get from training. They seem to be part of a signal that sends a message to the body, telling it to increase muscle size, muscle function, and oxygen carrying capacity. This allows us to perform that same exercise workload in the future with less stress on the body, a process known as adaptation. So if we are consuming excessive amounts of antioxidants, we may actually be interfering with these signals. There is actually some research that supports this. For instance, a 2008 study from the American Journal of Clinical Nutrition found that 1 gram/day supplementation of vitamin C for 8 weeks tended to negatively affect endurance performance. Men who supplemented with vitamin C had less of an increase in VO2max over 8 weeks of training when compared to men who did not supplement with vitamin C (Gomez-Cabrera et al., 2008). Other studies, however, show no negative performance effects from antioxidant supplementation (Yfanti C et al., 2010).
One exception to these equivocal findings may be the use of antioxidant supplements during periods of training or competition at altitude. Several studies have found vitamin E supplementation to be superior to placebo with respect to improving various aerobic performance measures during high altitude exposure (Kobayashi, 1974; Tatsuo et al., 1968). In a low-oxygen environment, greater amounts of ROS are likely produced, and vitamin E can help to reduce oxidative stress. These benefits may only be acute, however. As shown by Subudhi et al. (2006), antioxidant supplementation for 3 weeks before and 14 days during altitude exposure prevented a decline in cycling power at ventilatory threshold after two days of altitude exposure. After nine days, however, no differences were seen between the antioxidant and placebo groups.
Overall, the evidence for antioxidant supplementation in athletes is rather weak, and in some cases, may actually hinder performance. Some exceptions may exist, such as during the first few days of altitude exposure, but caution should still be used. The best strategy for most athletes is to eat an abundant amount of fruits and vegetables, as well as to include some rich sources of vitamin E—almonds, sunflower seeds, peanut butter, spinach and broccoli. Mix in spices and herbs like cinnamon, curcumin, ginger, and curry power, and you’ll be on your way to quenching just the right amount of ROS.
References: -Gomez-Cabrera et al. (2008). Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance. American Journal of Clinical Nutrition, 87 (1), 142-149 -Kobayashi Y. Effect of vitamin E on aerobic work performance in man during acute exposure to hypoxic hypoxia Dissertation. Albuquerque: University of New Mexico; 1974. - Subudhi et al. Changes in ventilatory threshold at high altitude: effect of antioxidants. Medicine & Science in Sports & Exercise, 38 (8), 1425-1431 -Tatsuo N, Hiroshi K, Yunichiro A, Takershi M, and Kimiko S. The effect of vitamin E on endurance. Asian Med J 1968;11:619-626. -Yfanti C et al. (2010). Antioxidant supplementation does not alter endurance training adaptation. Medicine & Science in Sports & Exercise, 42 (7), 1388-95.
Beans: The Ultimate “Super Food” (7/8/2010)
Nutrition is a field loaded with trends and fads, and probably no movement represents this better than the “super food” craze. You’d have to have lived under a rock for the past 10 years to not have heard the term “super food” attached to a host of edible—and some inedible—fodder. Blueberries, acai berries, broccoli, spinach, almonds…the list goes on and on. While there is really no agreement on what the term “super food” actually means, some foods certainly are packed with a variety of nutrients that can be health promoting. Of all the so-called “super foods”, beans are often the most under-appreciated and under-utilized.
So what is a bean exactly? Well it depends on if you’re botanist or a nutritionist. From a plant perspective, beans can be split into two groups: oilseeds and grain beans. Oilseeds include soybeans and nuts, while grain beans consist of dry beans, chickpeas, fava beans, lima beans, and lentil. Grain beans will be the focus of this blog article and will be simply referred to as beans.
Nutritionally speaking, beans cross multiple food groups and can sometimes be difficult to classify. Compared to most plant foods, beans are high in protein: ½ cup has 7-8 grams of protein. The United States Department of Agriculture’s MyPyramid program recognizes beans as a vegetable and a protein. Furthermore, beans are a source of carbohydrate, and although ½ cup of beans has as much carbohydrate as a slice of whole wheat bread, it has at least twice as much fiber. In addition, the type of carbohydrate causes less of a spike in blood sugar. The fiber in beans is also particularly effective at lowering cholesterol, especially the heart disease promoting “LDL” type. The fact that they are low in fat, sodium, and are free of cholesterol also makes them heart-friendly.
Beans are also high in many essential vitamins and minerals. They contain at least 10% of the daily values for folate, iron, magnesium, potassium, copper, and manganese. They are also a good source of zinc and selenium. Probably the most surprising benefit of beans is their extraordinary antioxidant capacity. A 2004 analysis of foods from the Journal of Agricultural and Food Chemistry found that small red beans had the highest antioxidant capacity of any food tested, even more so than antioxidant powerhouse blueberries. Pinto beans also made the top 5. Indeed, other research shows that eating more beans translates into less oxidative stress in the body, which can contribute to premature aging and chronic diseases. A 2007 study published in journal Free Radical Research had two groups of obese individuals follow a calorie restricted diet for 8 weeks. One group included beans in their diet 4 times per week, while the other group did not include beans in their diet. While both groups lost weight, the group that ate the beans lost more weight, and the bean group showed decreased oxidative stress after the 8 weeks.
Beans offer a unique nutritional profile that can benefit almost any individual. What’s more, they are relatively cheap, versatile, and convenient. So whether you desire to lose weight, lower your cholesterol, or just improve your overall health, beans can truly be considered a “super food”.
References: -Crujeiras et al. (2007). A hypocaloric diet enriched in legumes specifically mitigates lipid peroxidation in obese subjects. Free Radical Research, 41 (4): 498–506 -Winham, Webb, and Barr. Beans and good health. Nutrition Today, 43 (5), 201-209 -Wu et al. (2004). Lipophilic and hydrophilic antioxidant capacities of common foods in the United States. Journal of Agricultural Food Chemistry, 52, 4026-4037
Eating for Your Skin (5/28/2010)
With the rays of the summer sun intensifying by the minute, it’s time to start paying attention to the largest organ on your body: your skin of course! Excessive exposure to the sun has long been known to be a risk factor for premature skin aging. A quick Google search of the key terms “skin” and “diet” reveals a plethora of diet schemes and supplement concoctions promising to transform your skin into that of a Greek goddess. In reality, though, credible research linking diet and skin health comes few and far between….let’s just say it’s not at the top of the priority list of the major national health organizations.
Despite the relative lack of research on diet and skin health, there are a few common themes that seem to reoccur in the studies out there. A British Journal of Nutrition study published in early 2010 examined the link between certain dietary nutrients and measures of skin aging such as elasticity, hydration, and facial wrinkles. Some interesting revelations are worth noting. For facial wrinkles (I like to think of it as the Freddy Kreuger index), only two out of the 14 diet components measured were significantly related to increased wrinkling. Green and yellow vegetable intake had a positive effect on facial wrinkles (the more they ate, the fewer wrinkles they had). Interestingly, the dietary scapegoat saturated fat also showed a positive effect. Don’t get too enthusiastic about pounding all the bacon and butter you want in hopes of achieving glowing skin, however. This study was on Japanese women, who traditionally have low saturated fat intakes compared to Americans.
A 2001 study from the Journal of the American College of Nutrition examined the diets of Greek and Swedish born elderly individuals and the relationship to skin aging on the back of the hand. They found that a high intake of vegetables, olive oil, fish, and legumes along with a lower intake of milk products, butter, margarine and sugar was associated with less skin damage and wrinkling. Some caution is definitely warranted, though, as the education level and socioeconomic status of the individuals were not considered. That makes it particularly difficult to tell whether the reduced skin damage was actually due to their diet, as opposed to other positive health behaviors that seem to be more common in people who follow nutritious diets.
What about other oft-claimed beneficial practices, such as drinking 8 glasses of water per day? To be certain, skin does require a minimum level of water to maintain optimal function (as does every cell in the body). In truth, however, there is basically no real science behind the 8 glasses of water per day mantra. Fluid needs are highly individual and vary with environmental conditions and physical activity levels. In addition, essentially all foods contain some amount of water, so there is little value in chugging water all day long.
It seems clear that your diet can have impact on your skin. In addition to avoiding excessive sun exposure and habits like smoking, you could try the following to keep your skin healthy for a lifetime: : · Dark green/red/yellow vegetables once per day· Black/red/kidney beans 2-3 times per week· Fish high in omega-3 fats (salmon, mackerel, herring) twice per week· Source of monounsaturated fat once per day (1 Tbsp olive oil or 10-15 almonds)· Limit added sugar in your diet to less than 6 teaspoons day (1/3 cup)· Use butter and margarine as infrequently as possible· Choose low-fat versions of dairy products
References: -Nagata et al. (2010). Association of dietary fat, vegetables, and antioxidant nutrients with skin ageing in Japanese women. British Journal of Nutrition. 103, 1493-1498 -Purba et al. (2001). Skin wrinkling: can food make a difference? Journal of the American College of Nutrition. 20, (1), 71-80
Good Fat, Bad Fat? (5/24/10)
Dietary fat is a modern-day conundrum for many Americans. Beginning in the 1980s, major health organizations like the National Institutes of Health and the U.S. Surgeon General’s Office began warning of the dangers of dietary fat. The market became flooded with thousands of new low-fat and non-fat versions of everything from cookies to ice cream, all under the auspices and recommendations of health experts. Even the USDA’s Food Guide Pyramid took aim, relegating dietary fat to the top of the dietary pyramid, recommending to use it “sparingly”. Much of the interest in dietary fat and its relationship to disease originated from research done by Ancel Keys at the University of Minnesota. His seminal research, known as the Seven Countries Study, showed strong relationships between heart disease, blood cholesterol levels, and dietary fat (mainly saturated fat) in many countries across the world. Some, though, criticized even this early discovery because many countries were not included in the analysis, which may have affected the findings.
A government group called the National Cholesterol Education Program was created in 1985 to educate the public on the benefits of lowering blood cholesterol. Part of their recommendations focused on diet, called the Step 1 and Step 2 diets. The Step 1 diet advocated a total fat intake of less than 30% of calories, saturated fat of less than 10% of calories, and dietary cholesterol of less than 300 mg/day. If the Step 1 diet failed to achieve blood cholesterol goals, the Step 2 diet suggested saturated fat and dietary cholesterol be reduced even more, to less than 7% of calories and 200 mg/day. Finally in 2000 and with a revision in 2006, the Therapeutic Lifestyle Changes Diet was introduced, which changed the total fat goal (among some other suggestions) from less than 30% of calories to 25-35% of calories.The reason for the change was based on the observations that when total fat drops below 20% of calories, “good” HDL cholesterol decreases without any further drops in “bad” LDL cholesterol. Got all that? Neither do most Americans....
These recommendations were expected to prevent several diseases, such as heart disease and certain cancers. Unfortunately, many of the experimental studies (actually changing the subjects’ diets) failed to show the benefits that were long expected. For example, the Women’s Health Initiative (WHI) Randomized Controlled Dietary Modification Trial had over 19,000 women change their diet to a low-fat, high-fruit and vegetable diet. The women were followed for over 8 years. Those on the diet did not reduce their risk of heart disease or stroke compared to women who continued to eat as they pleased. Other large studies have shown similar disappointing results.
So is this evidence that low-fat diets don’t work? The answer is probably Yes and No. On closer inspection, several explanations may help to reconcile these contradictory findings. While the women from the WHI study reduced their total fat and saturated fat intake, they never got below 7% of calories from saturated fat. In addition, they only increased their fruit and vegetable intake by about 1 serving/day, probably not enough to make a significant impact. Similarly, saturated fat intake has actually decreased for the average American in the past 30 years. Unfortunately, most of this has come in the form of refined carbohydrates like white bread, sugar, and crackers. We now know that this strategy does no good.
Quite simply, the issue of a high-fat versus low-fat is best illustrated by two cultures thousands of miles across the globe from each other. On the island of Okinawa off of the coast of Japan, inhabitants customarily follow an extremely low-fat diet, with less than 10% of calories coming from fat. Another island in the Mediterranean, Crete, is on the opposite end of the dietary fat spectrum, with about 30-40% of their calories coming from fat. So what do both of these groups of people have in common? The answer is longevity and amazingly low-rates of heart disease. And why do these seemingly different diets contribute to the same long-lasting health benefits? For sure, cultural, genetic, and environmental factors are involved, but both of these groups consume mainly plant based, nutrient dense diets high in fruits, vegetables, and whole grains. How high is high? Okinawans reportedly consume around 7 servings of vegetables, 7 servings of whole grains, and 2-4 servings of fruit per day. That contrasts in comparison to the average American, who consumes 1 fruit and 2 vegetable servings a day (NHANES survey).
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