Nutrition & Physical Activity

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Diet soda vs. water for a workout: And the winner is...

Dear Thirsty,

On your marks, get set, go! Staying hydrated while you’re hitting the gym (or the pavement) is extremely important for an active body. While diet soda may boast zero calories and zero sugar, it is not the Holy Grail to achieving a healthy level of hydration. Diet soda does hydrate the body, but not as well as water. Soaking up the following information can help you stick to water and stay hydrated on the field:

  • Some diet sodas contain caffeine, which has mild diuretic properties and can increase urination. This decreases the amount of water available to the body — quite detrimental if you’re trying to quench your thirst. Caffeine also increases stomach acid levels, which can cause stomach irritation while you are exercising. Lastly, caffeine is addictive and in large quantities can cause insomnia, jitteriness, headaches, anxiety disorders, and fatigue.
  • Diet sodas contain significant amounts of sodium, which draws water out of the body's cells and can contribute to dehydration.
  • Sugary sweet sodas may cause your brain to crave other sweets — not ideal if you’re exercising for health and fitness. In a study done on rodents, artificial sweetener caused the animals to steadily increase their calorie consumption.
  • Both carbonic acid and phosphoric acid are commonly found in sodas. As a result, drinking too much of the bubbly can corrode the enamel of your teeth.

While the FDA has concluded that aspartame is safe for consumption, it has been linked to a number of side effects such as dizziness, migraines, memory loss, diarrhea, and mood swings. If you are concerned about the safety of aspartame, you can always check the labels of the foods and drinks before you buy them. You may also want to consider discussing any concerns with a health care provider, who may be able to suggest other sweetening alternatives. For example, you can give your water a little pizzazz by adding a wedge of lime or lemon.

The bottom line is that water is the best (and cheapest!) hydrator on the market. Moreover, decreasing on your diet soda consumption may be beneficial to your health as well. Check out the related Q&As below for more information. For tips on cutting down, check out Getting off colas, sodas, pop, fiz...oh, whatever! Drink up and keep moving!


Chia seeds and nutrition

Dear Reader,

Looking for something that will help you grow as big as a “chia pet?” Chia seeds are edible seeds that come from the desert plant Salvia hispanica, which is grown in Mexico and dates back to Mayan and Aztec cultures. "Chia" means strength, and folklore has it that these cultures used the tiny black and white seeds as an energy booster. Chia seeds are packed with nutrients, and therefore thought to be a healthy addition to your diet. In order to get the nutritional benefits, it is generally recommended to eat 20 grams of chia seeds (a little bit under two tablespoons), twice per day. However, the appropriate amount of chia seeds depends on several factors such as user's age, health, and several other conditions.

Chia seeds contain omega-3 fatty acids, carbohydrates, protein, fiber, antioxidants, and calcium. One ounce (about two tablespoons) contains 139 calories, 4 g of protein, 9 g of fat, 12 g of carbohydrates, 11 g of fiber, plus vitamins and minerals. Chia seeds can be easily added to foods, drinks, and baked goods. They can also be mixed with water and made into a gel.

So what’s all the hype? People eat chia seeds for diabetes, high blood pressure, and to reduce the risk of heart disease and stroke. However, there is currently no good evidence to support chia consumption for these uses. People have also tried using chia seeds as a weight loss aid, as the high fiber content is thought to suppress appetite and ultimately help with weight loss. There’s not much support for this claim.  One study found that eating chia seeds had no effects on body weight, body fat, or changes in appetite over a 12-week period. However, studies have shown that a particular variety of chia seeds, marketed under Salba, can reduce certain risk factors for heart disease such as blood pressure, clotting factors, and inflammation.

With all natural supplements come precautions. If you have food allergies (especially to sesame or mustard seeds) or are on high blood pressure medications or blood thinners, ask your healthcare provider before adding chia to your diet. Also, eating chia seeds is not recommended for pregnant or breastfeeding women, as little is known about the risks. Finally, chia seeds are high in alpha-linolenic acid, which in high doses may increase the risk of prostate cancer.  

May your new seeds of knowledge grow into a happy and healthy plant!


Hot yoga injuries

Dear Tentative Yogi,

Like many forms of yoga, hot yoga has become immensely popular. It can indeed have many benefits. But it may also carry some unique risks, especially when practiced in a western context — one which sometimes (even implicitly) emphasizes competition, calorie burning, and getting a good (read: intense) workout, over mindfulness, inward focus, form, and awareness of the body. In addition, classes are sometimes large and instructors may not always be as attentive to individuals in the class as would be ideal. There are a few other concerns to keep in mind when practicing hot yoga; however, if you stay mindful of these, the benefits will generally outweigh the risks.

The heat that is a part of Bikram and other forms of hot yoga, does serve to increase blood flow to the muscles and to increase collagen elasticity. Studies have shown that heat in combination with stretching can increase flexibility and range-of-motion (interestingly, studies also demonstrate that cold can increase flexibility because it decreases muscle spasms, pain reception, and sometimes dilating blood vessels). The increased heat can also decrease a person’s pain perception. This, combined with the increased flexibility that comes with stretching in the heat, can cause some people to push their body farther than it’s ready to go. If you’re doing poses that stretch beyond your limits, or muscling through poses, you are likely making yourself more susceptible to injury. Staying mindful of your body and your limits, as well as practicing with a trained instructor can help to decrease the chances of injury.

Another note of caution: The humid heat in hot yoga increases sweating, which can increase the chances for dehydration, also making one more susceptible to injury. Please, please stay hydrated! Be cautious of overheating. Your body naturally cools itself down using mechanisms such as sweating; however, crowded, hot yoga rooms can make this challenging. Read Does sweating release toxins? from the Go Ask Alice! archives for more information.

Supplementing your yoga with weight or resistance training will help decrease susceptibility to injury. Strength (not just flexibility) helps guard against pulls and strains. In fact, some research shows that weak, flexible muscles are more prone to injury than are strong, stiff muscles.

If one maintains an awareness of one’s limits and “listens” to her or his body, the “hotness” of hot yoga does not necessarily present a danger. Either way, kudos to you for finding a form of exercise that you enjoy!

Take care,


Diet soda and insulin spikes

Dear Reader,

It appears that the jury is out on the influence of artificial sweeteners on the body’s blood sugar and insulin response. While some studies (primarily on animals) have pointed to a link between sweeteners and insulin spikes, others have failed to find such a link. More research needs to be done in order to come up with more conclusive information.

It is important to note that there are multiple types of artificial sweeteners, including aspartame (NutraSweet, Equal), saccharin (Sweet’N Low), sucralose (Splenda), and Acesulfame potassium (Sunett). Each of these sweet substitutes is chemically unique. While some may be sweet and induce a slight insulin response, others may be bitter and affect other parts of the body. Therefore, more research needs to be done to determine the effects of each brand of sweetener on the body. Back to the lab bench!

Unfortunately, it is unlikely that there is a single winning method for all people trying to avoid insulin spikes. It is important that you find the right sweetener that works for you. For example, if you test your blood sugar and find that you do not have a response to artificial sweeteners, or that consuming these substances with a meal mitigates insulin spikes, then you may be able to continue this habit. If you are concerned about your insulin and blood sugar levels, it is recommended to speak with a health care provider. Columbia students can make an appointment to see a health care provider by calling Medical Services at x4-2284 or by logging in to Open Communicator.

Stay sweet & healthy!


Sea salt

Dear Reader,

Who knew the selection of salts could be so satiating? Kosher salt, sea salt, and table (regular) salt all have the same basic nutritional value, despite the fact that sea salt is often marketed as the more natural or healthier choice. In other words, the chemical compositions of various types of salts are all 40 percent sodium and 60 percent chloride. Therefore, the health effects of the three types of salt are generally the same. The differences between these three varieties are mostly limited to taste, texture, and granule size.

Kosher salt tends to be larger in grain size. As a result, kosher salt may have less sodium per teaspoon than regular table salt. Kosher salt contains no preservatives, and can be derived from either seawater or underground sources. The name “kosher” comes from the koshering process performed on the salt. Kosher salt is particularly good for preserving foods because its large crystals draw moisture out of meats and other foods more effectively than other salts.

True to its namesake, sea salt is derived from seawater. While sea salt may not be larger in grain size than table salt, it contains more minerals due to its deep-sea origins. This is because sea salt is harvested from evaporated seawater and receives little or no processing. These minerals may slightly flavor and color the salt. Sea salts may contain less sodium per teaspoon than table salt. Here’s a tip: it might not be worth forking out extra money for sea salt if you’re going to cook or dissolve it in liquid, as this may cause it to lose its unique flavor.

Regular table salt is mined from underground salt deposits, and includes a small portion of calcium silicate, an anti-caking agent added to prevent clumping. It possesses very fine crystals and a sharp taste. Because of its fine grain, a single teaspoon of table salt contains more salt than a tablespoon of kosher or sea salt.

Your body needs only a very tiny amount of salt to stay healthy. Most people ingest too much salt, mostly from eating processed foods. If you are concerned about the effects of salt on high blood pressure, the following tips can help you limit your sodium intake:

  • Go light on the saltshaker! Try to refrain from adding a lot of salt to your food.
  • Pay attention to the ingredients in processed foods, which can be chock full of salt. Scan the ingredients for keywords such as soda, sodium, or the symbol “Na”.
  • Spice up your food — in a different way! Instead of adding salt, try using herbs (fresh or dried) or spices.

So there you have it. Kosher salt, sea salt, and table salt all contain the same basic nutritional values. As for any other information you hear regarding the topic at hand — take it with a grain of salt!


Vitamin D deficiency

Dear Reader,

Ahh, good ‘ole vitamin D — one of the most versatile and important vitamins. When combined with calcium, vitamin D promotes calcium absorption, helps maintain bone health, and is crucial for bone growth and remodeling. Adequate levels of vitamin D can prevent rickets in children and help protect adults from osteoporosis. Vitamin D is also important for regulation of cell growth, neuromuscular and immune function, and reduction of inflammation. Many genes that regulate cell growth, differentiation, and cell life cycle are also regulated in part by vitamin D.

The 25-hydroxy vitamin D test is currently the most accurate way to measure a person’s vitamin D level. Normal levels of vitamin D range between 30 and 74 ng/mL, and levels below 12 ng/mL are considered high risk for vitamin D deficiency. Speaking with your health care provider may help you better understand your test results. Extremely low levels of vitamin D can cause bones to become thin, brittle, or misshapen. Vitamin D deficiency is also associated with an elevated risk of cancers of the colon, breast, and prostate; high blood pressure and cardiovascular disease; osteoarthritis; and immune-system abnormalities.

Those who cannot get adequate sun exposure may consider the use of a vitamin D supplement. People with serious deficiencies may be prescribed weekly doses of up to 50,000 units (I.U.) until their levels are corrected. It appears that at nutritional doses, D2 and D3 supplements are equally effective. At high doses though, D3 may be more effective than D2. Speaking with your health care provider again can help you decide which supplement is best for you. The current recommended intake of vitamin D, as established by the Institute of Medicine, is as follows:

  • 200 I.U. (5 micrograms, or 0.005 mg) per day from birth to age 50 years old
  • 400 I.U. per day for adults ages 50 to 70 years old
  • 600 I.U. for adults older than 70 years old
  • 1000-2000 I.U. for certain populations, such as sun-deprived individuals, pregnant and lactating women

Aside from vitamin D supplements, most people obtain the recommended amount through exposure to UVB rays in sunlight. Researchers have found that exposure to the sun without sunscreen (except on your face, of course!) between 5 and 30 minutes per day, at least twice per week, can lead to sufficient vitamin D production. Remember though, too much UV exposure can increase your risk of skin cancer. If you’ve already got your vitamin D time covered, cover up your body with adequate clothing and sunscreen.

Unfortunately, very few foods in nature contain vitamin D. Most vitamin D in the American diet comes from fortified foods such as cereal or milk. For example, cow’s milk in the U.S. is fortified with 100 I.U. per cup. Fatty fish and fish liver oils are also good natural sources. Small amounts of vitamin D may also be found in beef liver, cheese, egg yolks, and some types of mushrooms.

It is important to be aware that certain medications can impair the body’s ability to absorb and metabolize vitamin D. For example, corticosteroids (such as prednisone) can reduce calcium absorption and impair vitamin D metabolism. Both phenobarbital and phenytoin (sold as Dilantin), used in preventing and controlling epileptic seizures, increase the metabolism of vitamin D to inactive compounds and reduce calcium absorption. Additionally, the cholesterol drug cholestyramine (sold under Questran, LoCholest, and Prevalite) can reduce the absorption of vitamin D and other fat-soluble vitamins. Make sure your doctor knows if you are taking any other medications. If you are a Columbia student, you can make an appointment with a registered dietitian by contacting Medical Services (Morningside) or the Student Health Service (CUMC).

Here’s to happy bodies and healthy vitamin D levels!


Sleep or exercise?

Dear Tired and Flabby,

Don’t run yourself ragged! It seems that there is a larger issue here: not getting enough sleep. Sleep deprivation increases your risk of developing cognitive problems and chronic diseases such as diabetes and obesity. Exercising every day is a great way to help you get back into a healthy sleep routine. In addition, regular exercise may help control weight, protect against certain health conditions and diseases, boost energy, improve your mood, and have a positive effect on your sex life (oh, baby!). However, research has shown that a lack of sleep can undermine the awesome health benefits of exercise.

Sleep affects important hormonal activity tied to appetite and therefore has a direct impact on your ability to lose weight (i.e. body fat). Leptin (a hormone secreted by our fat cells) and ghrelin (a hormone secreted in our stomachs) work like a checks and balances system in the body and control your feelings of fullness and hunger. When you don't get enough sleep, your leptin levels drop and your ghrelin levels rise. In other words, sleep deprivation makes you more likely to crave sugary, high-carb foods (thanks to higher levels of ghrelin) that have the potential to sabotage your diet. Finally, sleep releases growth hormone, which is extremely important for tissue repair — an important function when you’re working your muscles.

Have you considered why you may be experiencing insomnia? For example, have you been under any added stress or feeling considerable anxiety? It may be helpful to try some relaxation exercises before bed, such as listening to a guided meditation, or perhaps taking a warm bath or listening to calm music. A walk after dinner may even help you wind down and start to focus on relaxing a bit in preparation for bedtime.

You can get more sleep! Here are some tips for upping your ZZZ score:

  • Limit caffeine, alcohol, or nicotine close to your bedtime. These products have all been shown to interfere with sleep quality, which in turn may keep you awake at night.
  • Limit naps to 20 to 30 minutes. Try to get your sleep at night, but, if napping during the day, keep 'em short and sweet to reduce grogginess and to maintain alertness and performance without disrupting your nighttime sleep.
  • Exercise regularly, but try to finish up at least three hours before you plan to go to bed. While exercising daily is known to improve sleep quality exercising close to your bedtime may increase alertness, keeping you awake.
  • Avoid late night eating. This may make you less comfortable when settling down for bed.
  • Keep a regular bedtime schedule, even on weekends.
  • Avoid exposing yourself to bright lights right before going to bed, such as bright computer and cell phone screens.
  • Try to make sure your bed is used only for bedtime activities. Studying in your bed may cause your mind to associate your bed with work, thus cueing your mind to think about work instead of rest.
  • Create a sleeping environment that is dark, quiet, cool, and comfortable. 

Moral of the story: If you “are very tired and have been getting little sleep for several days,” your best bet is to hit the hay. Better to catch up on those zzz’s than hit the gym or walking path sleep deprived and fuzzy-eyed. Exercise can help you stay toned and get back into a healthy sleeping pattern, but it’s necessary to get enough sleep so you can actually reap the health benefits of exercise.


For more information, check out these recommended resources:

Columbia Health's a!sleep website

Stressbusters (Morningside)

Cooking for partners with different nutritional needs

Dear the Pounds Thief,

Kudos to both of you for trying to maintain healthy eating patterns during the major life transition of moving in together! Your question seems to indicate that you two have different nutritional needs, but not wildly different diets. The good news is that your nutritional needs may not be as different as you think; what will vary more are you daily caloric requirements. The other good news is that partners who have very different diets move in together all the time: vegans with carnivorous dairy lovers, gluten-free and gluten-loving people, diabetics with non-diabetics, pescatarians with vegetarians. You get the idea. So you’re in good company as you try to figure this all out.

Two primary factors determine one’s caloric needs: body size and activity level. Sedentary people (regardless of gender) need about 13 calories per pound of body weight per day. Moderately active people need about 16 calories for every pound per day, and very active people should boost that amount to about 18. People tend to over-estimate how much protein they need. As a general rule, people of any activity level and gender and size need only 15 percent of their daily calories to be from proteins. Excess protein can decrease calcium absorption and cause calcium to be lost in the urine. Excess protein is also stored as fat, so it can contribute to weight gain from fat, not only muscle. Excess protein can also cause kidney stones. Typically 6-8 ounces of meat will cover it, less if you are eating other protein rich foods like beans and some cheeses.

Approximately 45-65 percent of your daily calories should be from carbohydrates. The more fiber in those sources, the better. It’s also great if your carbohydrates are coming from dark leafy greens like kale and spinach, because these will also have lots of iron and B vitamins.

Fat consumption should be below 30-35 percent of your total caloric intake (or 20-25 percent if weight loss is a concern). Try to avoid trans fats (found in some types of margarine, fried foods at restaurants, and store-bought snacks). And try to have more mono-unsaturated fats (avocadoes, olive oil, flax, fish) then saturated fats (found in dairy, vegetable oil, and meats).

Couples with different caloric or dietary needs may need to do a bit more planning and be more intentional about their menus than others. There is no rule that says you have to eat exactly the same items at the same time and in the same amounts. Here are some tips to help with meal times:

  • If you’re worried about portion control, try to be mindful of how much you put on your plate at a time. People often feel compelled to finish what’s on their plate, even if they are no longer hungry. Try loading your plate with less and then going back for more if you’re still hungry.
  • Try to keep fewer unhealthy snacks in the house. If they aren’t there, you’re less likely to consume the “empty calories” from these snacks when you get hungry.
  • Speaking of snacks, do you snack throughout the day? If not, consider trying it! People will eat less at meal times if they have been snacking some throughout the day. This also is easier on your metabolism and digestive system. Try keeping lots of healthy snacks around: whole grain breads, yogurt, granola, fruit, carrots, raisins, walnuts, and celery are all good, healthy, lean yet filling snack choices that will put a dent in your appetite by dinner.
  • Along these same lines, don’t skip meals! This will make you hungrier by dinner and that’s when people are most likely to eat more than needed.
  • Buy foods you both like and alternate nights cooking for each other. On the night your partner cooks for you, eat the foods you most prefer. If it is not quite enough for him, perhaps he can cook up a side dish to give him a little extra. On the night you cook for him, make him a meal he loves. If he doesn’t want veggies, cook up a side of veggies for yourself. This can be a great way to honor each other’s dietary preferences.
  • Do you like cooking together? Consider taking a cooking class or checking out some recipes online that might incorporate food ingredients that you both would enjoy. Make it a fun project of discovery.

As you noted, having different activity levels and different dietary needs in the same household can be a source of stress. But, working through and honoring these differences can also strengthen a relationship. As the poet Rainer Maria Rilke said: “Once the realization is accepted that even between the closest human beings infinite distances continue, a wonderful living side by side can grow, if they succeed in loving the distance between them, which makes it possible for each to see the other whole against the sky.”

Here’s to love and food,


How much rest between runs?

Dear G.,

Kudos to you for developing a healthy workout habit! No matter how fit and healthy you are, all runners require rest periods in order to allow the body to recover and grow stronger. How much rest one needs depends on a lot of factors, such as the type of training one is doing, ageing, injuries, illness, and increases in exercise intensity. Some runners take only one day off per week and find that this is sufficient. Others find that they are their healthiest when they take more. After an intense run, muscles need about 48 hours to recover. Do you find that you are quite sore after running for three days? If so, are you still sore or stiff after your day of rest? If so, this may be an indication that you could benefit from a bit more rest, but there are other causes of soreness besides not enough rest. In addition to soreness, significant weight loss, difficulty sleeping, or an elevated resting heart rate are other indicators you may need more rest.

Running is one the best endurance sports you can do — it gives your cardiovascular system a great workout. It also gives your body quite a beating and this is one reason why rest periods for runners are particularly important. But a day off doesn’t have to mean a day off from all physical activity. Many runners (and other athletes, as well) find that they benefit from what’s known as the “active rest.” This involves doing some other activity in place of running and toning down the intensity level somewhat. Your rest day activity could involve a brisk walk, racquetball, swimming, or riding a bike, for instance. All of these are more low-impact than endurance running and give your body a different type of work out, allowing you to use different muscle groups.

Rest allows your muscles, tendons, ligaments, and bones the opportunity to recover from the beating they take during your 50 minute runs, but there are other ways to ease the stress on your body:

  • A good stretch both before and after your run.
  • Frequently replacing your running shoes.
  • A long warm up (run slowly and ideally on a flat surface for the first 10-15 minutes of your run).
  • A cool down period (5-10 minutes of a brisk walk or very slow jog at the end of your run).
  • Hydration! Drink plenty of water.

Another good argument for changing up the type of exercise you do on your rest days is that your body “adjusts” to your workouts, which means that over time, if you do the same activity, your body becomes so good at it that the workout produces fewer benefits, even as you increase the intensity. Changing the type of activity “shocks” your body, as it is doing something it is less accustomed to and thus working harder. This extra hard work allows you to reap more benefits. Plus, variety keeps life interesting.

But even if you stick with your 50 minute runs 3-4 times a week, you are doing a great thing for your body. Good for you and keep it up! If you are a Columbia student, check out CU Move for tons of resources, information, and ideas for staying active. Your body will thank you.

Happy trails,


Muscle building product (HGH)?

Dear Da Windex Guy,

The cheapest and safest way to get tickets to the gun show is to hit the gym! Whereas human growth hormone (HGH) products like Sytropin may help your friend beef up, it only does so in the short-term while also beefing up other hormones in the body that may lead to some unintended side effects (as you suspected). As a general rule, take caution when using any substance that isn’t approved by the Food and Drug Administration (FDA) as well as using prescription drugs without the okay from a health care provider.

Initial development and prescription of HGH products were for people with growth disorders and for people with diseases such as AIDS who had growth hormone deficiencies. Now HGH has gotten a reputation for being abused in the sports world and also used controversially to increase milk production in cows. Normally, the pituitary gland (located in the base of the brain) regulates the natural release of HGH. Products like Sytropin introduce synthetic HGH into the body promoting cell growth, reproduction, and regeneration. This, in turn, reduces fat in the body, and increases lean body mass (muscle mass and bone density) and exercise capacity. However, though HGH may increase bulk, there is no solid proof that it increases strength or improves athletic ability (at least not in the long-term).

Your hesitation in using Sytropin or other HGH products is warranted because there is no solid evidence to prove their safety. HGH is only legally available by prescription and scientists still aren’t certain whether HGH taken in pill or spray form (like Sytropin) are effective. Other side effects of HGH use may include:

  • Swelling in the limbs.
  • Pain in the joints and muscles.
  • Gynecomastia (swelling of the breast tissue in men).
  • Higher risk for heart disease and diabetes due to increases in insulin and cortisol.
  • Potential insulin resistance.

List adapted from the Mayo Clinic

Those who reap the most benefits of using HGH are people who have problems naturally producing growth hormone. The average Jane or Joe looking to boost their muscle volume will likely have the same luck (sans potential HGH side effects) if they stick to a healthy diet and workout regime. Though it may seem tempting to buy scalped tickets to the gun show from Sytropin, investing the extra time and effort into physical exercise is the best and safest approach to securing front row seats. Check out the exercise and diet tips in the Related Q&As below for more information.


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