Nutrition & Physical Activity

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Will probiotic-enriched yogurt aid digestion?

Dear Reader,

It's wise to keep a healthy skepticism about the marketing efforts of some of these huge food corporations. Dannon's probiotic-fortified yogurt, Activia, is certainly an example of a highly promoted product. In recent years, the global market for "functional foods," has grown to billions of dollars annually, and since these supplement-food hybrids are appearing on the shelves ever more rapidly, the FDA doesn't have a chance to evaluate all of their claims. While there is evidence that probiotics do help to improve digestion and gastronomic health, it is hard to say that one brand over another is more effective at doing so.

Probiotics, beneficial bacteria that live in the small intestine, are believed to improve digestion. These gut-friendly bacteria actually help you to digest and eliminate your food, while crowding out the unhealthy gut-dwelling bacteria that cause gas, constipation, and bloating. Studies have shown that certain probiotics can help relieve irritable bowel syndrome, diarrhea, constipation, atopic eczema, and may also help protect against various infections and colon cancer. Researchers have found that stressed-out rats have benefited from a serving of water containing certain probiotics. Not a flattering comparison for us people, who might feel like stressed-out rats from time to time, but the findings of the study may be helpful. Probiotics are found in many types of fermented foods, like yogurt, sauerkraut, tempeh, and miso.

Regular yogurt is made using these live cultures, and serves up a healthy serving of them with each spoonful. But your question, is Dannon's Activia more effective in providing these results than regular good old-fashioned yogurt, is one that begs a good answer. Dannon (of course) says yes. Their Activia yogurt contains Bifidus regularis, a probiotic strain trademarked by Dannon that is not in other yogurts, and they claim that this particular strain speeds wastes through the digestive system and improves immunity in the intestines more effectively than other strains.

Dannon says that their Bifidus regularis, "survives passage through the digestive tract, arriving in the colon as a living culture," whereas other cultures can be destroyed by stomach acids and the natural process of digestion. The consumer reports lab has confirmed Dannon's claim, reporting that about three million of the original three billion probiotic organisms in a four-ounce serving of Activia made it through the stomach to the colon.

There is one other difference you mentioned between this yogurt and the others: the price. Activia typically costs more per ounce than regular Dannon yogurt. There are also other brands on the market that offer yogurts containing probiotics that are similar to those in Activia. If you're willing to spoon out the extra cash for yogurts with these particular probiotics and have noticed a decrease in stomach grumblings as a result, it seems like it working for you and might be worth it. However, now that you know that all yogurts contain healthy amounts of probiotics, it might be interesting to see if those regular yogurts feel just as good as the one with all the advertising. Eat up!

Alice

Food coma

Dear Reader,

The symptoms you describe sound like what many people call the "food coma." Sometimes, after eating a holiday meal, a big dinner or lunch, or even sometimes after meals that didn't seem that big, you may feel a bit drowsy. Some medical conditions can cause this feeling, including anemia, kidney dysfunction, sleep disorders, infections, or an electrolyte imbalance just to name a few. But even people who don't have any of these medical conditions may still feel tired after eating, because this symptom is also a consequence of normal digestion!

Why? Because our bodies spend a lot of energy digesting food. The stomach mechanically churns the food, produces acid to break the food into tiny pieces, and then controls the rate this broken down food can enter the intestines. In the intestines, enzymes use energy to further break down and absorb food particles into the body. For humans, it is normal for the rate of energy use to increase by 25 to 50 percent after a meal. This increased bodily activity could contribute to your feeling flushed after eating.

One explanation for your drowsiness lies in one of the hormones released during digestion — cholecystokinin. Commonly referred to as CCK, this hormone helps make you feel full, but also activates the areas in the brain associated with sleep. So after eating, when CCK levels rise to tell you you're full, you may also start to feel sleepy. Additionally, meals high in carbohydrates can increase the levels of tryptophan (an amino acid) in the blood. In the brain, tryptophan is converted into serotonin (a neurotransmitter that makes people feel both happy and sleepy). This boost in serotonin could also cause someone to feel tired.  

Since you don't feel tired after every meal, you may want to keep a food journal to see what types of food have you craving a post-lunch nap. If carbohydrate-rich or heavy foods like pizza, pasta, or panini slow you down, you could opt for a salad, soup, or sushi on days when you have a lot of work to do in the afternoon. You could also try eating several smaller meals throughout the day, rather than a big lunch, to avoid overwhelming your digestive system.  

Feeling tired after eating is a common experience, and not necessarily linked to a medical condition. However, if you feel your symptoms may be related to a medical problem, it's always a good idea to visit your health care provider, especially if your fatigue begins to seriously impair your ability to get your work done. Students at Columbia can contact Medical Services (Morningside campus) or the Student Health Services (CUMC).

Best of luck in staying alert during your post-meal endeavors,

Alice

Mercury poisoning: Something fishy about too much tuna?

Dear Reader,

Fish can be an important part of a healthy diet; it's loaded with high-quality protein and omega-3 fatty acids and low in saturated fat and cholesterol. It’s also true that nearly all fish have at least trace amounts of methylmercury. The good news is that many of the commonly purchased fish in the United States, including several varieties of tuna, typically have lower levels of mercury and are safe to eat if the amount you consume doesn't exceed the weekly recommended serving size.

To answer your question specifically, Albacore (white) tuna and light tuna are the two most common kinds of canned tuna. Due to its larger size, white tuna contains significantly more mercury — up to three times more — than light tuna. The EPA guidelines state that it's safe to eat up to twelve ounces of light tuna (or any fish low in mercury) a week or six ounces of white tuna a week. Considering that the standard weight of a can of tuna is six ounces, you may be putting yourself at a risk for mercury poisoning if you're eating two to five cans per day.

So why worry about mercury? It's considered a pollutant and is released into the environment, largely from factories and other industrial settings. It eventually travels to streams and oceans where microorganisms present in the water turn it into methylmercury. Fish then absorb this chemical into their bodies from the water. Mercury levels in the fish depend on what they eat, how long they tend to live, and where they are in the underwater food chain. Larger fish typically contain higher levels of mercury not only because they're heavier and have more surface area to absorb mercury, but also because they eat smaller mercury-containing fish, which increases the larger fish's mercury content. Because of this, the Environmental Protection Agency (EPA) recommends staying away from shark, swordfish, king mackerel, and tilefish from the Gulf of Mexico, since on average they have higher levels of mercury.  

Most of the warnings about mercury poisoning are targeted to young children and pregnant women because exposure to mercury during development can cause neurological defects, including impairments in cognition, memory, attention, language, and fine motor skills. This is especially of concern because infants born with these impairments have been observed even when the mother showed no symptoms of poisoning. Mercury poisoning in adults can cause numbness in fingers and toes, muscle weakness, and speech, hearing, and walking impairments. And so far, research has not found that mercury exposure in humans is associated with cancer, but human studies are limited. If you find yourself experiencing any of these symptoms, it’s best to visit your health care provider as soon as possible. If you feel fine but are scared of prematurely swimming with the fishes, you might want to switch up your fish or seafood meals to include a variety of low-mercury choices, such as salmon, shrimp, pollock, catfish, cod, or tilapia.

The National Resources Defense Council's Mercury Contamination in Fish - Consumer Guide to Mercury in Fish provides tools that can help make this transition proceed swimmingly. It contains a list that informs consumers of the frequency that a certain fish can be eaten safely, as well as a mercury calculator that generates a safe value for fish intake based on a person's weight and type of fish. Lastly, if cost is of concern, there are many additional options for protein and nutrients on the cheap. You could also try substituting the tasty and affordable tuna with non-fish sources of protein, such as chopped canned chicken, lean deli meats, or beans; these can also be part of a healthy diet without breaking the bank.

Alice

Blue corn chips — Are they healthier?

Dear Reader,

It's often said that the more (naturally) colorful your plate is, the healthier that meal is for you. This saying holds true in the corn arena: Blue corn does contain more of the amino acid lysine and the antioxidant anthocyanin than "regular" yellow corn; however, it loses much of these nutrients when it's processed into a chip. Blue corn chips may be slightly more nutritious in this sense, but if you're trying to increase the amounts of lysine or antioxidants in your diet, fresh and whole fruits, vegetables, and lean proteins are much better sources.

Research has also found that blue corn tortillas (fresh, not fried into chips) contain more protein than their yellow or white corn counterparts. In addition, blue corn tortillas have a lower starch content and lower glycemic index (GI) than regular corn tortillas. Both of these factors may be helpful to people on low GI diets, such as diabetics, because food with a lower starch and low GI breaks down more slowly into sugars absorbed by the blood stream and can help people avoid spikes in blood sugar levels.

Keep in mind that chips of any color are often fried and can be high in fat and calories, so it's probably best to not make them a regular snack. Baked chips or crackers may be a healthier alternative, especially if they're made with whole grains. Look for the words "whole grain" or "whole" before the grain's name on the ingredients label to make sure it falls into this category. Fiber is another important consideration in a healthy snack, and not all whole grain products are high in fiber, so be sure to look at fiber content on the nutrition label. For more information on whole grains and fiber, check out some of the Related Q&As below.

Alice

Weightloss diets for vegetarians, and everybody

Dear Reader,

Fortunately for people who wish to lose weight, there are universal rules that apply, regardless of your typical diet — whether you're a vegetarian or omnivore. First, to lose weight a person has to use more energy (calories) than s/he takes in. To achieve this deficit you can either make dietary changes (so you're taking in less calories), get more physical activity (so you're using more calories in a day), or you can make changes in both areas. Experts recommend making both dietary changes and getting more physical activity for the best results.

It takes a deficit of about 3500 calories to lose one pound of body weight. This means if you are able to cut 500 calories per day from your regular diet you should be able to lose a pound a week (a healthy weight loss rate). It may be beneficial to consider finding the right balance of increasing your physical activity and decreasing caloric intake. You can check out the ChooseMyPlate.gov SuperTracker as a resource that can help you calculate how many calories you need per day, what nutrients are in the foods you eat, and how many calories you burn doing different exercises.

Some suggestions for dietary changes to reduce calories:

  • Steam, boil or bake foods instead of frying in butter or oil.
  • Sauté foods in vegetable broth, wine, or water instead of oil.
  • Limit of high-fat condiments (like mayonnaise, margarine, sour cream, cream cheese, salad dressing, etc.).
  • Try low-fat dairy products and nut- or peanut butter. Vegetarians sometimes begin to rely heavily on these foods as sources of protein, but low-fat dairy and nut products provide the same amount of protein as their full-fat counterparts.
  • Add beans and legumes to your diet as low-fat sources of protein.
  • Eat actual fruit or vegetables rather than drinking them in juice or smoothie form. The fiber in fresh produce works well to satisfy hunger.
  • Substitute water, tea, and diet beverages for regular soda, juices, and other high-sugar drinks.
  • Limit the amount of alcoholic beverages consumed (empty calories for everyone).
  • Begin lunch or dinner with a broth-based, vegetable filled soup or a large salad with a small amount of low-fat or fat-free dressing. These foods take longer to eat and can help curb your hunger so you don't overeat during the rest of the meal.
  • Be mindful of portion sizes — read nutrition fact labels to find out serving sizes. Some rules of thumb:
    • A medium apple or orange is the size of a tennis ball.
    • A medium potato is the size of a computer mouse.
    • An average bagel is the size of a hockey puck.
    • An ounce of cheese is size of four dice.

Some suggestions for incorporating more physical activity into your day:

  • Take the stairs as often as possible.
  • Park at the far end of the parking lot or get off the bus or subway a stop early.
  • Schedule your cardiovascular exercise (walking, jogging, swimming, biking, frantically cleaning your apartment before visitors come over, etc.) so you know you will be able to fit it in. If you're at Columbia, you can participate with CU Move to help stay motivated with your physical activity efforts and earn incentives.  Check out the site to learn more. 

Hopefully, you'll find some of these suggestions new and helpful. Good luck!

Alice

Why do I choose not to eat?

Dear Reader,

Kudos for taking the first step and reaching out to ask about your feelings and behaviors. The symptoms you describe, including going long periods of time without eating, may be dangerous and could have long-term effects on your health. Feeling down once in a while is common but the depression you mention, and the fear of becoming more depressed if you begin eating more regularly, may be a serious clinical depression (and could be what is affecting your eating habits).

Skipping meals and intentionally not eating for periods of time (sometimes called fasting) can become addictive. Many people who fast experience euphoric feelings of well-being, feelings that are likely harmless when fasting in moderation. However, this "high" may mask feelings of being down or depressed and could explain why you feel better when you avoid eating (and why you continue to go long periods of time without food). Fasting too often can be detrimental to your health because your body is denied nutrients and energy it needs.

Avoiding food could also be a sign of a serious eating disorder: anorexia nervosa. See Eating disorders vs. normal eating for more information about the signs and symptoms of eating disorders. People with anorexia sometimes describe a feeling of control when they don't eat; a feeling that may be very powerful. You mention that you feel like you can't change anything in your life; controlling what you eat and skipping meals may be a way of feeling in control. Talking with a counselor or other mental health care provider about your feelings and eating habits may help you to understand your behaviors and feel more in control of your life. 

Talking with a mental health care provider may be a good way to begin to think about other factors in your life that may be contributing to your desire to skip meals, especially when you are around your friends. If you aren't sure how to begin a conversation with a counselor, you could simply tell her or him what you have written here, or you could ask one of your concerned friends to go along and help explain what s/he has noticed about your eating habits. Gaining an understanding of why you are feeling this way is an important step to overcoming these feelings and being able to eat normally without fear of becoming depressed.

It may take some work to find the right counselor and confront your fear of becoming depressed, but you already took an important (and difficult!) first step to seeking help. It also sounds like you have good friends who want to support you. Best of luck as you take the next steps to living a healthier, happier life.

Alice

For more information or to make an appointment, check out these recommended resources:

Counseling and Psychological Services (Morningside)

Mental Health Service (CUMC)


I need an effective, short-term weight loss and toning plan

Dear Annie,

Bravo for incorporating physical activity into your schedule! Regular exercise increases energy levels, improves quality of sleep, and boosts self-esteem. In terms of the effectiveness of your routine, it's difficult to say. Losing weight and toning up is influenced by multiple factors, including height, weight, bone density, genetics, and previous exercise regimen. By "a few pounds," do you mean two or ten or more? When setting out to change your body, it's important to ask yourself if the change you are striving for is realistic. In terms of your desired outcome, first ask yourself, "is this a realistic goal for me?" If you are unsure, it is wise to consult a personal trainer, exercise physiologist, registered dietitian, or your health care provider.

Part of effectively setting and reaching a goal means establishing one, or several, measurement criteria. Are you using a scale to measure body weight? Are you measuring body/fat composition? Strength? Clothes size? Body image? It's important to keep consistent with your indicators to know if you are making progress. If you are using a scale to measure body weight (in pounds), keep a few things in mind:

  • Muscle weighs more than fat.
  • Women especially can be prone to minor weight fluctuations due to menstruation and other types of hormonal activity.
  • Water, an essential nutrient for all sorts of body functions, can tip the scale one way or another.

You can also incorporate some basic guidelines into your plan that will help you maintain an active lifestyle:

  • Start slowly and build over time. It is smart to start off with a goal of running one mile as a workout, with the intention of increasing distance over time. Many people drop out of their exercise program because they go too hard, too fast, too soon. Pacing yourself, especially at the beginning, will help you establish confidence, self-awareness, and a strong fitness base.
  • Incorporate variety into your exercise and eating routine. Including different types of food and activity into your schedule will help to maintain enjoyment and motivation. You mention running and abdominal exercises — are there other types of activities you enjoy? Decreasing body fat and increasing toning or strengthening of muscle requires a balance of cardiovascular and strength training activities. Also, a wide variety of foods will help to ensure that your body is getting the nutrients it needs. Eat plenty of fruits and vegetables and think about decorating your plate as though it were a box of Crayola crayons; that is, aim for foods that are rich in color, such as blueberries, spinach, salmon, and tomatoes.
  • Find a friend. Studies have shown social support plays an important role in exercise motivation and sticking to an activity plan. Recruit friends and/or family to join you on a run, accompany you to lunch, or offer support.
  • Get plenty of rest. Sleep deprivation often makes everything more challenging, and it is especially easy to skip exercise when you feel tired. Sleeping well may help you avoid that trap. Plus, the more you exercise, the more rest your muscles will need to repair and recover.
  • Make it fun. Listening to music, running in the sunshine, or playing a rousing game with friends are all examples of ways to maximize fun and make physical activity something you look forward to and enjoy.

Maintaining a healthy and nutritious diet is an integral part of living a healthy lifestyle and achieving your weight loss goals. Here are a few great tips that may help you achieve your nutrition goals:

  • Keep a food diary.
  • Choose a diet low in fat, saturated fat and cholesterol and moderate in sugars.
  • Eat smaller meals more often — this can help ward off hunger so that you won't overeat at your next meal. Healthy snack options include low fat yogurt, fruit, nuts, vegetables, and whole-grain crackers.
  • Prepare smaller portion sizes.
  • Eat your favorite foods in moderation to help stifle cravings and help you to stick to your diet.
  • Avoid unhealthy fad diets.
  • Eat slowly — this can help you feel more full and avoid overeating.

Above all, the most important thing to remember is that every individual is different. If you feel good about what you are doing and are making progress, keep going until you reach your realistic, healthy goal. You can do it!

Alice

Resistance training before aerobic exercise: Is this the right order?

Dear Pepe,

Any exercise, including both resistance training and aerobic exercise, will burn calories and help you reap the benefits of being active. The order of resistance training and aerobic exercise could make a slight difference in energy expenditure, but it is more important that you do both if you want to maximize calorie burn.

The theory you refer to is the process of glucose metabolism — or more simply put, how the body uses energy in exercise. Resistance training (anaerobic exercise) and aerobic exercise (such as running, walking, and swimming) are different in how they use energy. During anaerobic exercise (exercise that does not require oxygen to produce the necessary energy, or ATP, to carry out the activity) lactic acid is formed when pyruvate (an intermediate substance in glucose metabolism) combines with hydrogen, in the presence of lactate dehydrogenase. Lactic acid quickly diffuses from the muscle into the blood, where it is buffered and carried away. If this didn't occur, you'd tire out quickly. As you continue to work out, the clearance of lactic acid can't keep up with its formation. Lactic acid build-up inactivates certain enzymes that are involved in energy transfer and decreases the muscles' ability to contract — leading to more fatigue.

The order of aerobic and resistance training can be important in maintaining energy since the lactic acid that has remained in the muscle can be reversed back into an energy source (pyruvate) during recovery or when the pace of exercise is slowed. How quickly this recovery occurs varies individually. In this way, the order does affect calorie burn, since more energy may mean you can do more exercise. Although some lactic acid dissipates from the muscles and turns into glucose, this doesn't happen very quickly and it probably won't lead to a burst of energy.

Some studies have suggested that when resistance training takes place after aerobic exercise more energy is expended than when anaerobic exercise comes first. For example, a short bout of aerobic exercise (such as a brisk walk or light jog on the treadmill) before weight lifting will help your muscles warm up and could improve the calorie burn you get from your workout. Both resistance training and aerobic exercise burn calories, but in different ways. Any way you look at it, exercise puts some pep in your step.

Alice

Breakfast: The first chance to fill your tank

Dear Reader,

Regardless of your activity level, breakfast is an essential part of a healthful lifestyle and is also important for maintaining energy all day long. The motto here is anything for breakfast is better than nothing at all. Think of your body as a car and food as gas. Without gas, your car cannot get from one place to another.

The rate at which your body uses calories for energy is known as metabolism. Think of metabolism as the motor of your car. Metabolism is directly related to energy levels, so the higher your metabolism, the more energy you have throughout the day. When you are sleeping, your body naturally decreases its metabolism. When you wake up, there is an increase in metabolism, which peaks by noon. How much energy you have during this time is contingent on how much food calories your body has to use for energy. Breakfast becomes the first stop to the gas station before your road trip. So basically, eating breakfast actually helps maintain high energy levels throughout the day. In fact, the more hearty a breakfast you have, the more your metabolism motor will roar!

You do have to stick to some guidelines, of course, to promote optimal energy.

Calories

The best range of calories for breakfast is between 350 to 500. Below 350, your body will not fulfill the requirements for morning energy usage; above 500, your body may store unneeded calories as fat.

Balance

Plan and eat a balanced breakfast meal including complex carbohydrate, protein, fat, and a fruit or vegetable.

Quantity to Aim for

  • 1 to 2 servings of complex carbohydrates. One serving equals 1 piece of bread, ½ cup of cooked oatmeal, 1 cup of dry cereal, 1 English muffin, ½ bagel, ¼ cup of granola, 1 small muffin.
  • 1 serving of protein. For example, 1 cup of yogurt, ½ cup of cottage cheese, 1 ounce of cheese, 1 large egg, 2 ounces of smoked salmon, 1 cup of milk or soy milk, 2 tablespoons (T) of peanut butter, or ¼ cup of nuts or seeds.
  • 1 serving of fat. E.g., 1 teaspoon (t) of butter, 1 t of oil, 1 tablespoon (T) of cream cheese. But check your protein and carbohydrates for fat, there's no need to add extra if you have a serving of fat in your granola or omelet.
  • 1 serving of a fruit or vegetable. That is, 1 medium piece of fruit, 1 cup of cut fruit, ¼ cup dried fruit, 6 ounces of fruit juice, 1 cup of raw or ½ cup of cooked vegetables, 1 cup of vegetable juice.

Some examples of energizing breakfast meals include:

Meal Equal to
2 pieces of toast
2 T of peanut butter
1 medium banana
2 servings of complex carbohydrates
1 serving of protein
1 serving of fat
1 serving of fruit

½ bagel
1 T of cream cheese
2 ounces of smoked salmon
½ cup of sliced tomatoes

1 serving of complex carbohydrates
1 serving of fat
1 serving of protein
1 serving of vegetables

1 cup of cooked oatmeal with
1 cup of 2 percent fat milk
¼ cup of raisins
2 servings of complex carbohydrates
1 serving of protein
1 serving of fat
1 serving of fruit
1 small muffin
1 cup of plain low fat yogurt
1 cup of orange juice

1 serving of complex carbohydrates
1 serving of fat
1 serving of protein
1 serving of fruit

As you see, there are many delicious ways to get from point A to point B every morning. Imagine your surprise when you see the results with more energy!

Alice

Men and body image issues

Dear M,

You’re not alone — almost everyone struggles with self or body image at some point, and occasionally worrying about how you look is completely normal. However, if you find yourself constantly thinking about food, your body shape and size, or your appearance, and these thoughts get in the way of work or school, your emotional well-being, or your social life, you may have a more complex body image and/or eating issue.

It may be tricky to distinguish between a healthy diet and exercise routine and habits and behaviors that could be detrimental to your health. For example, restricting calorie intake and engaging in exercise are common elements of a weight loss diet, which is healthy and normal for individuals who have too much body fat. However, if you’re exercising or restricting calories so much so that your emotional and/or physical health suffers, you might be experiencing a more serious issue that requires more attention. If any of this rings true, a good place to start would be to meet with your healthcare provider or a counselor for proper assessment.

A common misconception is that body image issues and disordered eating only affects women. That’s simply not true. Men also experience varying degrees of body image disturbances, eating disorders, and other related issues just as women do. Many men keep these concerns secret, but estimates from the National Association of Anorexia Nervosa and Associated Disorders suggest that as many as 10 percent of those with eating disorders identify as male. Because men are less likely than women to disclose their disordered eating or exercise routines to their friends, loved ones, and doctors, diagnosis and treatment are often delayed. All this to say, reaching out was a brave thing to do!

Eating a healthy, well-balanced diet is essential in making sure you’re getting all of the nutrients you need, including an appropriate number of calories. A balanced diet includes foods from all of the different food groups, and eating at least three meals a day. A balanced diet should not include too much sugar or fat, although some fat is necessary in any diet. For more information about the food groups and to help figure out how much you should be eating, check out the United States Department of Agriculture’s guidelines as well as the get balanced! Guide for Healthier Eating.

Since you’re already wondering if your eating and exercise habits may be an issue, it's a good idea to talk to someone about food and body image to be sure you're on track for a healthy relationship with food and exercise. If you are a Columbia student, you can make an appointment with a member of the Eating Disorders Team, a multidisciplinary team of health care providers specializing in eating and body image concerns, by contacting Medical Services (Morningside) or the Student Health Service (CUMC) for an appointment. If you're not at Columbia, you can start by discussing your concerns with a healthcare provider or a counselor.

You took a big step in inquiring about these issues, and that isn't easy. You deserve to start feeling better about your weight and body image — hopefully some of this information will get you moving in that direction!

Alice

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