Nutrition Services

Ask a Nutritionist

Have questions about nutrition? Mary Flynn, PhD, RD, LDN, has answers. Flynn, a dietitian at The Miriam Hospital since 1984, is the co-author of The Pink Ribbon Diet and Low Fat Lies. The following questions were sent to Dr. Flynn by Lifespan website visitors.

When I'm on a special diet for gout, can I eat meat?

Meat is allowed but it is advisable to keep the portions small - less than 6 oz. A diet proportionately higher in meat and lower in carbohydrates, commonly referred to as "low carb," should be avoided. A starch (pasta, rice, grains, potatoes or beans) should be included in a meal that has meat. Lists of foods high in purines, which also are to be avoided, are readily available online and includes foods like anchovies, organ meats, mussels, scallops and sardines.

Are energy supplements safe?

Energy supplements should not be universally considered "safe." Energy products (drinks, powders, supplements) are a very unregulated industry and you never know exactly what you are ingesting. Most products list caffeine as a main ingredient, which they claim contributes to "energy." Caffeine does not give you energy, per se, it is a stimulant. Energy essentially comes from food, so any food can give you energy. Many of the other ingredients do not provide any benefits.

What should I be eating if I want to gain weight?

You may think that just eating a lot will help you gain weight. In reality, eating a lot of extra food may not actually increase weight gain. When too much food is eaten during a meal, the body cannot digest or absorb and metabolize those nutrients, so the energy from the food is lost as heat (the body temperature rises). Eating multiple smaller meals better allows the body to trap the calories. Please consult your primary care physician before radically changing your diet and exercise regimen.

What is the nutritional value of rice? Should you eat white rice or brown rice?

All types of rice mainly contain carbohydrate and some protein. Brown rice is better for you as it has the external part of the grain containing phytonutrients (beneficial organic components of plants) and some trace minerals. White rice is also healthy. It is a source of carbohydrate and B vitamins added after processing off the coating. The problem with a rice-heavy diet would be overeating it. It is easier to overeat refined grains, as opposed to whole grains. People who consistently eat whole grains weigh less and gain less weight over time.

Is drinking a large (500 calorie) fruit and yogurt smoothie three times a day a good way to lose weight?

I would say no for the following reasons:

  • As fat is helpful in preventing you from getting hungry between meals, and a fruit and yogurt smoothie is low in fat, I think you'd be more tempted to snack or overeat with the smoothies.
  • There is some science literature to suggest that we do not regulate liquid calories well, so drinking your meals may again lead to overeating as you will not be satisfied.
  • Weight loss comes down to eating less than you currently do and/or moving more. 1500 calories is a good level to start with but I would suggest increasing vegetables, grains and extra virgin olive oil for healthy fats.

Is it true that lecithin will dissolve built-up plaque in arteries?

I do not think that would be possible. Lecithin is a phospholipid and is found in the body, but I would think that eating it (i.e. pill form) would lead to digestion, rendering it non-functioning.

Should eggs be avoided? Are they healthy?

Eggs have never been related to increasing heart disease risk, or any other disease. The idea that eggs should be avoided to decrease heart disease risk may be the longest standing diet-related myth. I am continually amazed to hear patients say their physician recommended that they eat less eggs (and dismayed when it is a physician who is less than 50 years old!). I think the myth was started when blood cholesterol was shown to have some role in heart disease risk. Diet actually does not change blood cholesterol very much. (Another diet myth is that it will.) About 30 years ago, the American Heart Association started to say "eat a low-cholesterol diet" when I think what was meant was "eat a diet that lowers your blood cholesterol," even though such a diet does not really exist. Diet is most likely to change two of the lipoprotein particles that carry cholesterol, HDL and VLDL, which carries triglycerides (fat) from the liver. Low fat diets will raise triglycerides and lower HDL, neither change healthy. Comparing diets high in saturated fat to ones low in saturated fat can change LDL levels, but not on the order one would see with medications. Polyunsaturated fats, mainly vegetable oils, will oxidize LDL, which increases heart disease risk. 

I love eggs. They have great nutritional value for a very low cost, if you compare price per serving to other foods. A large egg has around 200 mg of cholesterol (not sure of the current amount listed as it seems to change). An ounce of most meats has around 30 mg, so 7 oz of meat has about the cholesterol in a large egg. But meat has a list of components that will increase your risk of heart disease, while the egg does not.

I hope that I have convinced you to add eggs to your diet!

How beneficial are bananas to a person's diet? Are there any foods that are similar to banana in terms of nutritional value (levels of potassium, vitamin B6, etc)?

Bananas, like all fruits (and vegetables), contain potassium, which has a number of important functions in the body. Somehow years ago, doctors starting 'prescribing' bananas when someone needed potassium. From this it seems many people think that only bananas have potassium. I think bananas were originally selected for potassium because they are widely available year round and many people like them. But they have no advantage over other fruits and many fruits are much more nutritious.

I love many green veggies and have always been told how important they are, but at the age of 61, I don't know if I should continue to eat them because of interactions with blood thinners.

Green vegetables are very healthy and they have a number of components that help to decrease your risk for cancer. They also contain vitamin K, which is involved in blood clotting. People who are on a blood thinner (e.g coumadin) are told to either not eat leafy greens as the vitamin K will interfere with the blood thinner or they have to eat the same amount of the vegetables every day (which is a healthier option and something newer that MD's will do). So, if you are not on coumadin, eat as many leafy greens as they will improve your health; if you are on coumadin, ask your MD if they would help you to be able to eat leafy greens by adjusting your medicine.

I read and hear about biotin lately. What is it, what is its function, how do we get it, and how much do we need?

Biotin is one of the B vitamins. It is needed in metabolic cycles that add carbons (as carbon dioxide), such as adding carbon to pyruvate at the beginning of gluconeogenesis (which is the making of glucose).

Biotin is in a lot of foods, but foods with higher amounts are whole grains, legumes, nuts and eggs. The amount you need is easily obtained through food. Bacteria in the intestinal tract also make biotin.

I think it has become "popular" due to being sold as vitamin "H" (to my knowledge, a made-up title). A true deficiency is a genetic disorder or can be induced in rats when they are fed large amounts of raw egg whites (a component in raw egg whites binds biotin). One of the side effects of biotin deficiency is hair loss (in infants, where the disorder is picked up) or fur loss in rats. From this, I have heard of MD's recommending biotin (vitamin H - which I have wondered if the H is for hair) for hair loss. There is no evidence that it works.

I am a 6'5" tall white male weighing between 210-230 pound who has diabetes. I want to know if 1,800 calories per day is enough to help me keep a healthy weight in general. If not, then what is the right amount of calories for me to take in daily?

The amount of calories (energy) needed daily is not an exact science. Not knowing if you are normal weight or need to lose weight, it would be impossible to say what you needed. I start all men for weight loss at 1,800 calories but if you are 6'5", I would think you could eat more (maybe 2,000—2,100 calories) and still lose weight. If you wanted to maintain your current weight, I would think you would need closer to 2,800 calories, but again, this is not knowing your weight history or if your current weight is a healthy one for you.

My doctor, a well respected internist, has been praising the "miracles" of Mila, the latest get healthy quick supplement. Have you heard of this and is it just a fad? Although I need help losing weight, I'm a bit of a skeptic when it comes to so-called mi

You are right to be skeptical. Mila is made from a seed (Salvia hispanica L) which is in the mint family. It is South American in origin and for some reason, supplement companies seem to keep bringing to market "miracles" from South America, often said to have an Aztec link.

The website for Mila offers no support for claims of health. It uses wording that is related to health functions but no studies to show the claims are true. It lists nutrients by gram of the seed versus other foods, which is misleading as it is a seed (very light in weight). For example, it says it has two times the potassium as in bananas. So if you took, say, a tablespoon of the seed, that might weigh less than 1/2 an ounce, which is less than 1/2 inch of a banana, you would get more potassium in the seed. This is an approach used by supplement literature, i.e., using comparisons of the product to common food items but the comparisons are not in common units or in units that would be consumed.

It is recommended that you proceed with caution before investing and/or using this supplement. There are no “miracle” drugs or supplements for weight loss.

I had a bout of diverticulitis and was told to avoid nuts, seeds, and certain foods like grapes because of their tough skin. When I asked the doctor about cherries, he deemed them okay. Is the a list somewhere of fruit skins that are too tough?

I had a bout of diverticulitis and was told to avoid nuts, seeds, and certain foods like grapes because of their tough skin. When I asked the doctor about cherries, he deemed them okay. Is the a list somewhere of fruit skins that are too tough?

What are the best post-workout foods, particularly for building muscle?

The amount of muscle you will build is mainly determined by genetics. If you are related to people who are muscular, your chances are much greater for developing larger muscles compared to someone from a more ‘linear’ inheritance. That said, to build muscle you need to work the muscle, meaning you need to put weight on the muscle to enlarge the fibers. As far as foods are concerned, muscle is made up of protein, and to build the muscle you must ingest some, though not the amount most people seem to think. Any diet that contains animal products (meat, dairy) has more than enough protein. Most vegetarian diets would also have enough protein; they just need to be better planned.

Immediately after an intensive workout is when the amino acids (which make up the dietary protein) are taken up by the muscle, so eating some protein within 30 minutes of finishing an intensive workout will help to make sure that you get the protein when you need it. However, this is assuming you have done an intensive workout; for many people the workout probably was not intensive enough for extra protein to be needed at this time. And, most people do not need to eat very much protein even if the workout was intensive. The literature on how much you need is not completely clear as it depends on your age, gender, size, etc. Besides protein, you also need about 30-50 grams of carbohydrate (depending on your size/ body weight) and some fluid. Without the carbohydrate, you will not take the amino acids into the muscle. This is when sports drinks can come in handy. Check the nutrition label to see how much you need to drink to get what you need for carbohydrate.

What are the best protein sources? How can I ensure that I get enough protein?

Protein is found in all animal products (meat, poultry, seafood, milk, cheese, eggs) and also found in many plant products such as starch foods (pasta, rice and other grains, potatoes, beans), as well as vegetables.

It is very easy to eat enough protein. While the easiest way to meet your protein needs is including animal products, most vegan diets (no animal products) contain sufficient amounts of protein. Any day you are eating any animal products, you are getting enough protein and probably more than you need. The amount of protein needed is based on the amount of lean tissue you are consuming (mainly muscle). The standard way to calculate daily per person need is 0.8 grams of protein per kilogram of ideal body weight (kg = pounds/2.2). Ideal body weight means you are not using an ‘overfat’ weight and is not that easy to figure.

I think people are overly concerned with eating enough protein and most people eat more than they need. Extra protein is not stored so eating too much means what you do not need can be stored as fat. Most women need about 45 to about 60 grams per day and men might need up to 75 grams per day. Most American diets contain far more than that.

Are fruits and vegetables more nutritious when they are in season?

Fruits and vegetables are more nutritious the longer they are kept on the plant so, in season, they could be more nutritious (but that is assuming you are eating ones kept on the plant longer). They are probably more likely to be kept on the plant longer at a local farmer’s market then what is bought in a store.

The problem with selling produce that has been kept longer on the plant is that it tends to be more difficult to transport, as most produce is fragile when it is very ripe. Produce that is frozen or canned can actually be more nutritious than what is sold as ‘fresh’ as it is kept on the plant longer if it will be processed than what is picked to be sold fresh.

I typically recommend frozen vegetables over fresh as I think they are healthier, you can keep more in your home (freezer) and they are all ready to use, which I think can increase use.

How much vitamin D we need? What foods are high in vitamin D?

It is nearly impossible to get enough vitamin D in the diet as very few foods contain vitamin D. We probably need at least 800 IU/day, which is very difficult to get with food. In theory, we can make all we need through our skin but we need sufficient time in the sun without sun block. Most people probably need a supplement of vitamin D3. To know for certain, have your blood tested first to see what you are starting with for a blood level.

How much extra virgin olive oil should someone try to consume each day?

I suggest at least of 2 tablespoons a day as that is the minimum studies show for when benefits are seen. Olive oil should be used for cooking meals, especially for preparing vegetables. My rule of thumb is 1 tablespoon of olive oil per cup of vegetables.

Learn more about the health benefits of olive oil.

Buying healthy foods seems expensive; do you have tips for making it more affordable?

What are often called foods for a "healthy diet" are typically items like lean meat and poultry, and lower fat dairy products, which are often the most expensive items on the grocery bill.

I have developed and am testing a plant-based olive oil diet. This diet is perfectly healthy and does not contain any meat, poultry or seafood and only small amounts of dairy products. I found it was so inexpensive when I used it for research, that I started a program in food pantries to teach the clients how to use it. When clients use the diet, their grocery receipts show significantly less money spent on food. The recipes for this program can be found on the RI Community Food Bank website under 'Raising the Bar on Nutrition."

I’ve got a sweet tooth and fruit doesn’t do the trick. What are some sweet but healthy snacks?

Sadly, there truly aren't any snacks that are sweet and healthy, as "sweet" means calories that do not provide health benefits. However, in order to combat the craving for sweet foods, eat more--yes, more--fat. I find when people do not have enough fat in the meal their desire for sweets goes up between meals.

I suggest a healthy fat at all meals: nuts at breakfast and extra virgin olive oil at lunch and dinner, which should help to decrease your desire for sweet foods. You might also try canned fruit (in juice) or dried fruit, both healthy and sweeter than many fresh fruits found in the produce department.

Lattes, cappuccinos, mochas…what are the lowest-calorie choices when looking for a caffeine fix?

Different stores all tend to vary in what they add to these drinks. The best way to prevent yourself from accidentally overindulging is to ask for calorie information before you order, or visit the website to view nutritional information. If those options aren't available, simply avoid additions like syrups and other sweeteners, and cream, which can quickly increase the caloric count.