Ask a Dietitian: Answered Questions

Nutrition::Ask a Dietitian::Answered Questions

Your question might have already been answered by one of our experts. Read through other questions and answers about nutrition below.

Question: How much fat should I eat in a day if I want to lose weight?

There is no recommended amount of fat that persons should eat on a daily basis. Desirable fat intake is based on calorie need. According to the 2005 Dietary Guidelines for Americans, fat consumption should be no more than 35% of the total diet and no less than 20%. Only 10% of total fat intake should be from saturated fats. An excellent resource for helping with daily meal planning is: www.mypyramid.gov. This website provides an individual meal plan based on a person's sex, age, height/weight and activity level. Thank you for your interest in learning more about fat in the diet. Eating the appropriate amount of fat goes a long way to maintain health throughout the life cycle.

Question: My question is regarding the RDA of B12 for an adult female. I'm a vegetarian. I do eat a small amount of cheese, do not drink milk or eat eggs. I drink fortified soy milk with calcium and B12, as well as eat soy products containing B12. I'm just wondering if this is enough or should I be taking a daily supplement? If so how much per day?

The Recommended Daily Allowance for vitamin B12 for males and females 19 years and older is 2.4 micrograms per day. I recommend that you read the labels of these products that you are using, add up the amounts per serving that you are eating and compare that to the RDA to decide whether or not you need to take a supplement. The human body stores years' worth of vitamin B12, so nutritional deficiency of this vitamin is extremely rare. Elderly are the most at risk and those lacking a substance called intrinsic factor, which must be present for the absorption of B12. Intrinsic factor has nothing to do with diet, however. So, read those labels and drink that fortified soy milk and you should be okay.

Question: My 13 year-old daughter is on a diet. She is trying to stick to 1,200 calories a day. Is this healthy for a young girl?

One of my concerns with a 13 year-old being on a 1,200 calorie diet is that it is very restrictive. This plan is more than likely too difficult to stick with long-term and could be a set-up for failure. It would be much better to implement a plan that could be followed for life, otherwise this could lead to a lifetime of "yo-yo dieting". Develop healthy eating behaviors now for a lifetime of healthy weight. The following recommendations provide a good, basic guideline:

• Eating five-or-more servings of fruits and vegetables per day
• Eliminating junk food from the house
• Two-or-fewer hours of screen time per day, and no television in the room where the child sleeps
• One hour-or-more of physical activity
• No sugar-sweetened beverages
• Eating a daily breakfast
• Limiting meals outside the home
• Family meals should happen at least five to six times per week
• Allowing the child to self-regulate her meals and avoiding overly restrictive behaviors

The goal should be weight maintenance with growth that results in a decreasing body mass index. Weight loss should be no more than two pounds per week. Diets do not work! A practice of healthy eating along with physical activity over a period of time makes for a healthy mind, body and spirit!

Question: I eat fresh salmon three times per week. Is there any danger of ingesting too much mercury?

Because one could get many different answers on this subject based on opinion, I am referring you to the Environmental Protection Agency and Food and Drug Administration’s Web site on mercury and seafood. The link is: www.cfsan.fda.gov/~dms/admehg3.html.

Question: My daughter is suffering from seizures which started out of the blue a year and a half ago. The neurologist can't give me a reason, but he has seen a rise in seizures in children and can't give a definite reason why, but suspects the chemicals that are added to our food. I would like to put my daughter on an organic diet. Is that safe for a seven-year old?

I am so sorry to hear of your daughter's onset of seizures. How frustrating it is when the cause of such a traumatic occurrence cannot be explained. I understand why you want to try an organic diet. I would be willing to spend the extra money for organic food if it would improve my child's health. I do highly recommend that you speak with your child's physician and let him/her know that this is your intention and if there is anything else you may choose to do to try and avert this condition, such as supplements. It is important to the physician to know what changes have been made. Now, to answer your concern about the safety of an organic diet; I would say yes, it is safe for a child or an adult. Just avoiding all the processed foods out there would help anyone become healthier. If you would like some reliable information on organic diets, I encourage you to check out the American Dietetic Association Web site at: www.eatright.org. Just put "organic" into the search space there and it will bring up some information that may be helpful. I hope you do find a way to alleviate this condition and that your daughter enjoys a lifetime of excellent health.

Question: I'm obese and I’m trying to lose weight, but the problem is I don’t eat meat at all or most veggies. My diet is mostly pastas, fruit and breads. What should I do? Is there any type of pasta I can eat? I really need some help.

It appears that you are taking a big step towards weight loss in asking for some assistance. Your current diet may be okay but just in need of a little "tweaking". Pay attention to the amount of calories you take in each day through beverages. Many times liquid calories are overlooked when trying to reduce. Also, portion size is very important. We have become so accustomed to the huge portions we receive in restaurants, that we have a tendency to overfill the plate at every meal. I am sending you some web sites that will address portion sizes and some other helpful instruments as well. On www.mypyramid.gov, you will find a calculator that will show you how many calories you should consume in a day for safe weight loss. Two pounds per week is the recommended goal. Rapid weight loss is not recommended and rarely stays off anyway. So be patient with it. Remember, physical activity is a must! If you have been totally inactive, start out slowly and build up. It really does help to take the stairs instead of the elevator and park farther away from the store. Expend a little extra energy here and there throughout the day. Also check out: www.eatright.org, and of course, much of this information is also on our Web site here at: www.getfittn.com. As an ex-compulsive eater, I know that food intake is a very emotional activity. It really helps to keep feelings about yourself as positive as you possibly can so you will treat yourself better by not overindulging. If you are able, avoid people and situations that bring you down. Thinking positively about yourself will assist you in making healthier choices that you will benefit from. When we have negative thoughts about ourselves, we tend not to care as much about the consequences of our choices. So, now it is time to educate yourself on good nutrition through these web sites, stay positive, be patience with yourself and you will be successful! You can get there! Congratulations on taking the steps to move in a healthier and more positive direction!

Question: Which veggies are to be eaten raw? Which ones need to be cooked? And at what temperature since heat destroys the enzymes and nutrients?

The premise of a raw food diet is to cook foods below 160 degrees Fahrenheit to keep enzymes intact so that the body can better absorb nutrients in the food. The problem with this theory is that the body already makes the enzymes needed to digest and absorb foods. Also, cooking can actually increase the variety of nutrients that get released inside our digestive tract. Heat actually increases the sulfur-containing substances found in onions and garlic since it triggers some chemical reactions that create variations in those sulfur compounds. These same compounds help protect our health. When eating raw vegetables, other factors must also be considered when evaluating the nutritional quality of the food. How fresh is the raw vegetable? Significant nutrient loss occurs in raw vegetables if they have been picked too long before they have been eaten and have been exposed too long to light and air. How well will you chew the raw food before swallowing them? When a food is not cooked, the body depends much more heavily upon chewing to help prepare the vegetable for digestion. Cooking a vegetable -- even for a very short period like one minute -- can be a way of enhancing its digestibility. There is no recommendation on which vegetables to eat raw and which to cook. That depends on your personal preference. However, it is good practice to eat a combination of both raw and cooked vegetables. Keep up the great work on your diet by incorporating those veggies!

Q: I’ve read about trans fats, and all I can seem to find out is that they are bad.  If they’re that bad, why do people put them in food?  Can I completely get rid of all trans fats in my diet?

Fats, especially trans fats, have gotten a lot of press recently because of research showing that trans fats may be worse for your heart than naturally occurring saturated fats. Trans fats have been shown to boost harmful LDL-cholesterol in your blood, while at the same time lowering levels of protective HDL-cholesterol.  For this reason, it’s a good idea to choose fewer trans fats to help improve your heart health. So how did trans fats get into your food?  To answer that question, we need to take a quick look at food chemistry and food history.  There are two basic types of fats: saturated fats and unsaturated fats.  Saturated fats are generally solid at room temperature, while unsaturated fats are generally more liquid at room temperature.  Think about lard vs. vegetable oil—the lard is highly saturated and is solid at room temperature; the vegetable oil is highly unsaturated and is therefore liquid at room temperature. In the early 1900s, food chemists began to experiment with ways to make inexpensive vegetable oils into more solid fats for cooking and other applications.  They developed a process called “hydrogenation”, which, simply put, makes liquid (unsaturated) fats more solid (saturated).  Hydrogenated shortening was introduced in 1911 as a cheap substitute for lard.  Hydrogenated shortening (known by the trade names Crisco® and Spry®) has been a common staple in many American kitchens since then, and has also been used extensively by the food industry due to its cheap cost and long shelf life.  Unfortunately, the food chemists in the early 1900s didn’t know that the trans fats created during the hydrogenation process are unhealthy. It’s nearly impossible to completely eliminate trans fats from your diet, since trans fats are also found naturally in some meats and dairy foods.  The majority of trans fats in the American diet come from hydrogenated and partially hydrogenated fats in foods, so the best advice is to cut back on trans fats by knowing where they hide.  The good news is that due to new labeling laws, food companies are now required to list the amount of trans fats in their products.  This will help you to be a better food sleuth and reduce your intake of trans fats.

• Check the Nutrition Facts panel, and choose foods that are lower in trans fats.
• If a food label says “zero trans fat”, it means that the amount of trans fat is less than 0.5 grams per serving.
• Check ingredients on the food label for the words “hydrogenated” and “partially hydrogenated”.  These indicate higher levels of trans fats.
• Some examples of common foods with trans fats: margarine, cookies, frostings, snack cakes, pastries, pie crust.
• Eat more foods that contain very few, if any, trans fats.  Include more fruits, vegetables, whole-grain foods, fish, lean meat and poultry, nuts, and olive, canola, and safflower oils.
• Limit your intake of fried foods and commercially baked goods.

Q: I was recently diagnosed with high blood pressure, and I’m not sure what to do.  My grandmother had this problem, and her doctor told her not to eat any salt.  What can I do to lower my blood pressure?

According to the American Heart Association, approximately one in three adults in the United States have high blood pressure. Uncontrolled high blood pressure can lead to heart attack, stroke and kidney failure.  Unfortunately, because there are often no symptoms associated with high blood pressure, nearly one-third of these people don’t know they have it.  In fact, many people have high blood pressure for many years without knowing it.  That’s why high blood pressure is sometimes called the “silent killer”. If you have been diagnosed with high blood pressure, there are several things you can do.  First of all, you need to talk with your health care provider about screening tests that will help you know if your high blood pressure is affecting your overall health. These may include tests of your heart and kidney function.  It’s also a good idea to talk to your health professional about a referral to a registered dietitian to discuss your individualized dietary plan. High blood pressure is generally managed with a combination of two approaches: 1) lifestyle changes, and 2) prescription medications.  For many people, simple lifestyle changes are enough to manage blood pressure. Regardless of whether your health care provider suggests medications, lifestyle changes can help you reduce your risk of heart disease, stroke, and kidney disease.  Lifestyle changes generally include dietary changes, exercise and weight loss.

First, let’s talk about weight loss and exercise.  Weight loss can make a huge difference in your blood pressure -- even a loss of 5-10% of your total body weight can make a difference. If you are overweight, talk to your health care provider and Registered Dietitian about safe, healthy ways to lose weight.  Exercise can also help to strengthen your heart muscle, reduce blood pressure and improve your overall health. Talk to your health care provider about what kinds of exercise are right for you. Now, let’s move on to dietary changes.  Since a diet that is high in salt is linked to high blood pressure, you’re smart to choose foods with less salt.  For most people, the problem is that they have learned throughout their lifetime to like salty foods. The good news is you can retrain your taste buds to enjoy less salt. First, always taste foods before adding salt at the table. Many people routinely salt everything, and this can really add a lot of sodium to your diet. If your food still needs a flavor lift, try these tips:

• Try black pepper, red pepper, chili pepper, etc.  
• Add a splash of lemon juice or vinegar.  Herbed, balsamic, wine and rice vinegars each give a slightly different flavor.
• Shake on a salt-free herbal blend, or make your own salt-free herb or spice combinations.

Here are some ideas for spice blends to add flavor without adding salt.  Mix the ingredients and keep in an airtight container.  Use your own ideas and be creative.

Get the facts on high blood pressure, and learn how to live a healthier life.  Even though you have high blood pressure, you can reduce your risk of heart disease, stroke and kidney disease with the right lifestyle changes.  

Q: I have a family history of diabetes and I was recently told by my doctor that I am becoming insulin resistant. I am approximately 90 to 100-lbs. overweight. He tells me that if I lose the weight this issue should be resolved. I have started walking 30 minutes a day and I am trying to limit myself to 2500 calories a day.  Is this the right approach for me to take?

Congratulations on taking some very positive first steps toward a healthier lifestyle! Including exercise in your daily routine will definitely improve your health, and is also a great step toward weight loss. As you continue to exercise every day, you will likely see your energy levels increase and you'll probably start to feel better. Because of your family history, you have an increased risk of developing diabetes. Being overweight can contribute to the development of insulin resistance and diabetes, so you definitely need to aim for a healthy weight. Losing weight will help your cells function more normally and will help the insulin in your body to do its job more effectively. Every person is very different, and this means that each person's dietary needs are very unique. 

Here are some general tips on improving your diet to help you achieve a healthful weight:

• eat more fruits and vegetables every day
• choose foods that are low in saturated fat and cholesterol, and moderate in total fat, salt and sugar
• make at least half of your grains whole
• eat a wide variety of foods, and include foods from every food group

Decreasing the amount of calories you consume every day will certainly help you lose weight, but it's best to get individualized advice on just how many calories you need every day.  For this reason, I recommend that you talk with your health care provider about a referral to a registered dietitian. Through individualized counseling, a registered dietitian can help you lose weight healthfully, help you steer clear of fad diets and create a weight loss plan that fits your lifestyle and helps you reach your goals. 

Q: Do I need a daily multivitamin?

That’s a great question. There are several different answers depending on your needs. The simple answer is that many people can benefit from a daily multivitamin, but it’s really more complicated than that.  Because each person’s nutrient needs are different, each person’s need for supplemental vitamins and minerals is also different. For a normal, healthy adult who eats a healthful diet including a wide variety of foods from all food groups, a multivitamin supplement is probably not necessary but is unlikely to cause any harm.  If you are a healthy adult with no health problems and you want to take a multivitamin/mineral supplement to boost your health, it’s important to choose one that contains no more than 100% of the Recommended Daily Allowance (RDA) for most vitamins and minerals.  This is mainly because some vitamins and minerals, such as vitamin A can be toxic at high levels.

Are you a woman of childbearing age?  If so, most health professionals now recommend that you take a daily multivitamin that is fortified with at least 400 micrograms of folic acid.  Folic acid (also called folate) can help to prevent birth defects. Don’t wait until you are pregnant to start taking folic acid. Folic acid must be present in the body prior to pregnancy to protect against neural tube defects. Pregnant and breastfeeding women are also encouraged to take multivitamin/mineral supplements that are designed especially for their nutritional needs.  If you are a pregnant or breastfeeding woman, or a woman of childbearing age, talk to your health care provider about your individual needs for supplementation.

Remember that a multivitamin/mineral supplement can’t make up for poor food choices.  Even if you do choose to take a multivitamin, it’s still important to choose a healthful diet containing a wide variety of foods from all food groups.  Supplements do not function as food replacements, and have not been proven to boost energy, speed weight loss or improve your mental function.  It’s also important to know that unlike medications, supplements are not regulated by the government. Talk to your health care provider or a Registered Dietitian about your individual nutrient needs, and always tell your health care professional before you begin taking any kind of vitamin or mineral supplement.  Some vitamins and minerals can interact with medications you may already be taking, so it’s important to check with an expert first.

Q: My teenage daughter has gained a lot of weight over the last several months, and I’m concerned that she is becoming overweight.  What can I do to help her be healthier?

Weight is a sensitive issue for everyone, but it’s especially sensitive for children and teens. Children who are overweight are at higher risk for diabetes and many other chronic diseases, so it’s a good idea to help everyone in your family reach and maintain a healthful weight. Generally speaking, most health professionals do not recommend “dieting” for children and teens.  To manage weight, teens need healthful, realistic and safe lifestyle strategies which include both physical activity and a smart eating plan.  Above all, remember that it’s important to maintain a positive attitude—your understanding, love and support will help your daughter deal more effectively with any weight issues. The first step in dealing with any weight issue is to consult with your family health care provider about any underlying health issues. Make sure to discuss your plans for exercise and dietary changes. Your health care provider can help you decide what type of activities are most appropriate, and can also advise you on any safety issues regarding various types of exercise.

Here are some basic strategies to help your family develop a healthier lifestyle:

• Does your family snack on high-calorie foods?  Eliminate “trigger foods”, such as the sight of high-calorie foods (chips, cookies, etc.) in the house.
• Keep nutritious, low-calorie foods -- including colorful fruits and vegetables -- in the house at all times.  By making these foods convenient to choose, you will help your family make better food choices.
• Think about your family’s eating style.  Do you all eat on the run, or do you sit down for meals together?  Make gradual improvements together.
• Talk to your teenager.  Listen and offer support and alternatives for any issues that may trigger “emotional eating”.
• Do fun, active things together as a family.  Instead of watching TV, try playing a game or taking a walk.
• Avoid enforcing forbidden foods with your teen.  All foods can fit in the context of a healthful diet, but the important thing is to eat everything in moderation.

Your family health care provider may also recommend a consultation with a registered dietitian, who can help your family develop a plan for a healthier lifestyle, help you steer clear of fad diets and make sure that your teen is getting enough of the right nutrients.

Q: After reading about all of the recent E. coli outbreaks, I’m really afraid to eat what I normally do. Is it true that choosing organic foods will help me avoid E. coli?

Organic foods are often advertised as a healthier choice than other foods, but when it comes to food safety, organic foods carry the same risks as other foods. To understand E. coli infection, it’s first important to know from where this bacteria comes and how it is transmitted to humans.  There are many strains of the bacteria E. coli -- the one that causes severe illness is called E. coli O157:H7 (these numbers and letters refer to specific markers found on the bacterial cells).  E. coli lives in the intestines of healthy cattle, deer, goats and sheep.  Because these bacteria live in animal intestines, manure from these animals can carry the harmful E. coli O157:H7 bacteria. In the past, the most common food associated with E. coli was undercooked ground beef.  Meat can become contaminated during slaughter, and organisms can be accidentally mixed into the meat when it is ground.  Lately, however, E. coli infection from fresh fruits and vegetables has become more common. This is because manure can contaminate the environment, including streams that flow through fields where fruits and vegetables are grown.  Streams that are used for irrigation can also contain E. coli. E. coli infection causes diarrhea, and occasionally kidney failure. 

Person-to-person contact in families and day-care centers is another known source of infection.  Bacteria in the loose stools of infected persons can be passed to others because of poor handwashing.  This is particularly likely among toddlers who are not toilet-trained. Families and playmates of these children are also at high risk of becoming infected. So what can you do to effectively prevent E. coli infection?  First of all, it’s important to remember that contaminated foods look and smell normal. You can’t tell by looking at a food whether it’s infected or not. This means that you need to take care to wash all fruits and vegetables and thoroughly cook all meats before you eat them. Here are some tips to help you protect your family from E. coli infection:

• Cook all ground meat and hamburger thoroughly.  Because ground beef can turn brown before disease-causing bacteria are killed, you should use an instant-read food thermometer to make sure the internal temperature at the thickest part reads at least 160°F.
• If you are served an undercooked hamburger in a restaurant, send it back for further cooking.  You should ask for a fresh bun and a clean plate, too.
• Avoid cross-contamination in your kitchen.  Keep raw meat separate from ready-to-eat foods.  Wash hands, counters and utensils with hot soapy water after they touch raw meat. Never place cooked hamburgers or ground beef on the unwashed plate that touched raw beef.
• Drink only pasteurized milk, juice and cider. The pasteurization process kills E. coli and other bacteria that may be present.
• Wash all fruits and vegetables under running water.  This includes fruits and vegetables that will be peeled prior to eating them.
• Make sure that all members of your family wash their hands thoroughly with soap after using the bathroom.

If you suspect that you or a member of your family has been infected with E. coli or any other foodborne illness, contact your doctor immediately for medical care.  For more information on how to prevent E. coli and other foodborne illnesses, visit the Partnership for Food Safety Education at www.fightbac.org. 

Q: How does using a thermometer help keep my food safer?

Appliance thermometers are one of the easiest ways to help make sure foods are safe, but very few people actually use them. This is unfortunate, because appliance thermometers can help you and your family from getting sick. Foodborne illnesses (E. coli, salmonella, C. perfringens, etc.) are most often caused by overgrowth of bacteria in food.  Most foods contain some bacteria, that’s why it’s so important to either kill the bacteria or keep the bacteria from multiplying.  One of the critical factors in controlling bacterial growth is controlling the temperature of the food. Most bacteria grow very slowly at temperatures below 40°F, multiply rapidly between 40°F and 140°F, and are killed at temperatures above 140°F.  That’s why the temperature range between 40°F and 140°F are sometimes referred to as the “danger zone”. For safety, it’s important to keep foods at the proper cold temperature (below 40°F), and to cook them thoroughly to destroy bacteria. But how can you be sure if the refrigerator is cold enough, or if the oven is heating at the proper temperature? Appliance thermometers can help you find out if your food is cold or hot enough for safe eating. Your refrigerator thermometer should always read no higher than 40°F, and the freezer thermometer should read around 0°F.  If the temperature is higher, the food may not be safe. An oven thermometer can read temperatures from 100°F to 600°F.  You can leave an oven thermometer in the oven and check it during cooking to make sure your foods are being cooked at the proper temperature. To learn more about using appliance thermometers and food thermometers to keep your food safe, visit the Partnership for Food Safety Education at www.fightbac.org.

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