Category Archives: nutrition

Six foods that you should eat every week

Fast food and frozen dinners have become a large part of the modern diet, mostly because of convenience.  Poor food choices that include sugary drinks and greasy snacks contribute to the high incidence of obesity, particularly when combined with a sedentary life style.

Eating small portions will help you maintain a healthy weight, but when you eat less your diet must include all the essential vitamins and minerals for proper nutrition.  Here are six foods that eaten every week can help you to stay healthy.

1. Nonfat yogurt is source of protein and calcium as well as probiotic bacteria that keep disease-causing bacteria from getting established in the digestive system.

2. Sardines contain protein and essential minerals, but they are also a source of omega-3 fatty acids which are essential for the health of the brain and the eyes.  These long-chain polyunsaturated fatty acids are particularly important nutrients during pregnancy and early childhood.  Unlike larger long-lived fish like tuna and swordfish, sardines have a lower content of heavy metals like mercury because they are lower in the food chain.

3. Oatmeal is a source of soluble fiber that lowers cholesterol and promotes regularity.  Fiber is not a nutrient, but it helps to attenuate blood glucose spikes by reducing the absorption in the intestines.  In addition, fiber promotes growth of intestinal bacteria that produce short-chain fatty acids and Vitamin K.

4. Salad greens contain a wide variety of vitamins, phytonutrients and fiber.  Leafy greens contain Vitamin E, Vitamin C, beta-carotene, lycopene, lutein-zeaxanthin and many other chemical compounds essential for good health.

5. Berries are a good source of anthocyanin antioxidants and vitamins.

6. Nuts contain omega-3 and omega-6 fatty acids, as well as protein and fiber.  Nuts are generally high in calories due to their oil content, but these are good fats.  If you eat peanut butter or other nut butters, make sure that they do not contain hydrogenated oils or saturated fats like coconut oil or palm oil because these increase cholesterol levels.  Read the labels.

These six nutritious foods can be combined into delicious meals.  A bowl of oatmeal can be garnished with berries and nuts topped with a spoonful of yogurt.  Sardines served on a bed of mixed salad greens will also make an excellent meal.

Use the Diet Calculator

Improve your diet for the New Year

A few changes to your diet can improve your health dramatically. The improvements will not occur suddenly, but your body will be healthier over time. If you are overweight, or if you have high cholesterol or blood pressure, a proper diet can improve your health. The important thing to remember is that you have to maintain good eating habits. You cannot eat junk food frequently and expect to improve your health. Pastries, candies and greasy food should become a very, very small part of your diet.

If you want to be healthy, you have to eat nutritious food. Eat at least five servings of fruits and vegetables per day. The vegetables and fruits can be fresh, frozen, canned or dried, as long as they do not include added sugar or preservatives. Fruits and vegetables decrease the risks of cancer, type 2 diabetes and heart disease by increasing fiber and aiding weight loss. Cruciferous vegetables, such as broccoli, cauliflower, and watercress, have been shown to protect against cancer.[1] Brightly colored vegetables and berries have phytonutrients that serve as antioxidants that enhance immune response. Blueberries and raspberries are low in calories and have many essential nutrients.

Reduce your fat intake by avoiding greasy foods like pizza, potato chips, fatty meats and cured or smoked meats. You should not avoid all fats. The body needs omega-3 fats, which are good for the brain and eyes, and can be obtained by eating fish like salmon, mackerel, tuna and trout. Sunflower seeds and walnuts are vegetable sources of omega-3 fats. You should eat these foods three or four times per week to get an adequate amount of essential fatty acids.

Reduce starchy and sugary foods. Excessive consumption of carbohydrates leads to obesity and type 2 diabetes. One of the best changes that you can make to your diet is to avoid sweet soft drinks and to replace all refined flour products with whole-grain products. Try whole-wheat pasta, brown rice and grains like quinoa and bulgur wheat. These are easy to cook and can be used in salads, side dishes or main courses. The hardest thing to give up will be pastries and candies because our body has a built-in desire for sweets, but you must limit desserts to very small quantities.

Humans evolved on an omnivorous diet that included plants and animal products. Some nutrients, like Vitamin B12, can only be obtained from animal sources. Vegetarian meals that include milk and eggs can provide complete nutrition and may be an alternative way for decreasing meat in the diet. Vegetarian meals like a bowl of lentil soup with a cheese sandwich, or Cajun red beans and rice with a garden salad can be delicious and very satisfying.

To make your diet work, you have to get rid of the junk food in your kitchen. Donate to a food bank any food with hydrogenated fats, and anything high in sodium or with preservatives. Also, eliminate sodas and sugary drinks. Make room in your refrigerator for fresh produce and in your pantry for whole grain products. Start the new year with better menus for a healthier life.

[1] Keck AS, Finley JW., Cruciferous vegetables: cancer protective mechanisms of glucosinolate hydrolysis products and selenium, Integr Cancer Ther. 2004 Mar;3(1):5-12. PMID: 15035868

Omega-3 Fatty Acids

Salmon SandwichThe consumption of fish has played an important role in the evolution of humans.  The human brain consists approximately of 60% fat.  Fatty acids called ALA, DHA and EPA are concentrated in cell walls and the myelin sheaths of the neurons.  These long-chain fatty acids have an unsaturated double bond in the third carbon from the end, and thus are known chemically as omega-3 fatty acids.  These fats are essential for good health and must be included in the diet because the body cannot create them from other fats.  Some vegetable sources, such as walnuts and flax seed, contain ALA, but fish oil is the best source of DHA and EPA.  The body can convert ALA to DHA and EPA, but not very efficiently.

Omega-3 fatty acids are components of all cell membranes and a deficiency of these essential fatty acids can cause symptoms such as fatigue, poor memory, dry skin, heart problems, depression, and bad circulation.  Fish oil supplementation is generally safe when taken in low doses (3 grams or less per day), but there are some safety concerns when fish oil is taken in high doses because it may keep blood from clotting and can increase the chance of bleeding, particularly in combination with anticoagulants and blood thinners.

It is always better to get nutrients from foods rather than from supplements.  Natural foods, such as salmon, herring or other fish, have the essential fatty acids, but they also have protein, vitamins and minerals necessary for a healthy diet.  The picture above shows an open-faced sandwich with slices of smoked salmon on sour dough bread spread with a teaspoon of mustard, and garnished with slices of avocado and chopped dill.  This is a delicious way of getting your omega-3 fatty acids.

Learn more about Fatty Acids

Vitamins are harmful in large doses

Vitamins are necessary for a healthy life.  A proper diet can supply all the vitamins that our body needs, but vitamin deficiencies can result from diets that do not include a variety of vegetable and animal products.  People who don’t eat animal products for philosophical reasons (vegans) need to take Vitamin B12 supplements to avoid deficiencies that can cause anemia or nervous system damage.

The sale of vitamins in the United States is a multi-million dollar industry.  If you turn on the television at dinner time, you are likely to see many advertisements for vitamin pills and dietary supplements.  Many people self-medicate without consulting a dietitian or nutritionist and try to compensate for their bad diets by taking daily doses of vitamin and mineral supplements.  Also, many doctors find it easier to recommend vitamin pills, rather than educate their patients about nutrition.

Experimentation with large doses of vitamins was proposed by Nobel Laureate Linus Pauling, who claimed that gram quantities of Vitamin C could prevent colds and cure cancer.  Further scientific studies found that Vitamin C was not effective for colds or cancer.  There is a lot of popular appeal for the idea that if a little is good, more must be better.  But this is not so.  A healthy body can only be maintained through moderation.

In the 1950s, Denham Harman proposed the idea that damage from free radicals on the cells caused aging.  Free radicals are highly reactive unstable groups of atoms that can be neutralized with antioxidants.  Since Vitamin E is an antioxidant, many people started to take the vitamin in doses as high as 2000 IU per day, when the Recommended Daily Allowance (RDA) is only 22.4 IU.  However, large doses have been found to increase the risk of cancer, rather than reduce aging.  Researchers at the National Cancer Institute found that men who took a high daily dose of vitamin E (400 IU per day) had a 17 percent greater risk of developing prostate cancer.  The trial included 35,533 men in the U.S., Canada, and Puerto Rico who were monitored for 7 to 12 years.[1,2]

Vitamin A is a fat-soluble vitamin that is found in carrots, green leafy vegetables and liver.  Vitamin A toxicity develops after taking too much vitamin A for long periods. Excessive vitamin A intake is associated with increased risk of fracture.  Some of the symptoms of hypervitaminosis A are blurred vision, bone pain or swelling, and abnormal softening of the skull in children.[3]

What vitamins or minerals should you supplement?  Start by using a free web application for tracking your nutrition such as CRON-O-Meter. Enter the foods and the amounts that you eat in a typical week.  When you have data for one week, you can determine the deficiencies in your diet, and only then can you decide what supplements to take.  Most people find that they only need to supplement magnesium.  Calcium may also be necessary for those who don’t consume dairy products regularly.  A detailed analysis of the foods that you eat can lead you to make more nutritious choices.

Chemical Structure of Vitamins and Minerals

[1] Klein EA, et al., Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT), JAMA. 2011 Oct 12;306(14):1549-56. PMID: 21990298

[2] Lippman SM, et al., Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT), JAMA. 2009 Jan 7;301(1):39-51. Epub 2008 Dec 9. PMID: 19066370

[3] Zile M. Vitamin A deficiencies and excess. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 45.

Exercise before breakfast to burn fat

pancreasA recent survey found that over 63 percent of adults in the U.S. are either overweight or obese.  Most people know that diet and exercise can get the body back to normal shape, but diet and fitness plans generally do not discuss the mechanisms by which diets work.

The weight of the body is regulated by the digestive system, the respiratory system, and hormones from the pancreas.  Food provides proteins, fats and carbohydrates which are macronutrients absorbed by the digestive system and are used to build body tissues and provide energy.  The presence of carbohydrates in the blood causes the beta cells of the islets of Langerhans in the pancreas to release insulin.  Insulin is a hormone that regulates carbohydrate metabolism and causes cells to take up glucose from the blood and store it as glycogen in the liver and as fat in the skin, abdomen, hips and muscles.

The islets of Langerhans in the pancreas also have alpha cells that produce glucagon, a hormone that helps convert stored fat into carbohydrates, but the secretion of glucagon is inhibited by the presence of insulin.  Thus, the hormones secreted by the pancreas control the level of glucose in the body.  When we eat food, insulin reduces the level of sugar in the blood by converting it mostly to fat.  When we are hungry, glucagon raises the level of glucose in the blood by converting fat into carbohydrates through lipolysis.

When we lose weight, where does the lost body weight go?  Energy is extracted from the nutrients by the mitochondria in the cells.  The waste products are carbon dioxide, uric acid and ammonia.  These last two are nitrogen-containing compounds.  Uric acid is the result of oxidation of nucleic acids found in the DNA of the food that we eat, and ammonia is produced from the metabolism of proteins.  The liver combines ammonia and carbon dioxide into urea, and both, uric acid and urea are excreted in the urine, which is how the body removes waste nitrogen from the body.  The excess carbon dioxide from carbohydrate and fat metabolism is expelled through the lungs which also take into the body oxygen from the atmosphere.  So, the weight is lost through the urine produced by the kidneys and through the carbon dioxide exhaled by the lungs.

Exercise increases the rate of metabolism and promotes the breakdown of body tissues to produce waste products.  Every exhalation of breath carries some carbon dioxide that reduces the body weight by a corresponding amount, which is not very much.  One hour of exercise, such as walking at a brisk pace, burns 300 calories; this corresponds approximately to the calories in one bagel with a tablespoon of jelly.

The combination of exercise and a nutritious, limited calorie diet is crucial for weight reduction.  Exercising in the fasted state before breakfast improves insulin sensitivity and takes advantage of the fact that carbohydrate stores are burned during the night and the body switches to burning fat.  Exercise before eating maintains the fat-burning mode, and this can be extended by delaying breakfast for one hour after exercising.  It is important not to snack.  Even a small morsel of food can trigger the release of insulin and stop the fat-burning mode.

Learn more about Exercise

[1] Van Proeyen, K; Szlufcik, K; Nielens, H; Ramaekers, M; Hespel, P; Beneficial metabolic adaptations due to endurance exercise training in the fasted state, J Appl Physiol. 2011 January; 110(1): 236–245. PMCID: PMC3253005

[2] Van Proeyen K, Szlufcik K, Nielens H, Pelgrim K, Deldicque L, Hesselink M, Van Veldhoven PP, Hespel P., Training in the fasted state improves glucose tolerance during fat-rich diet, J Physiol. 2010 Nov 1;588(Pt 21):4289-302. PMID: 20837645

[3] Kiens, B; Skeletal muscle lipid metabolism in exercise and insulin resistance, Physiol Rev. 2006 Jan;86(1):205-43. PMID: 16371598

[4] Romijn JA, Coyle EF, Sidossis LS, Gastaldelli A, Horowitz JF, Endert E, Wolfe RR. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. Am J Physiol. 1993;265(3 Pt 1):E380–91. PMID: 8214047

Delicious pasta shapes – farfalle and garganelli

Everybody loves pasta, and it is not hard to make your own.  The pasta that you buy in the store is usually made only from flour and water.  When you make your own pasta, you can make it more nutritious by adding eggs like traditional Italian pasta.  You can also create fun shapes that are decorative and appetizing.

The picture above shows farfalle (butterflies) and garganelli tubes.  Farfalle are made by folding and pinching pasta squares, and the garganelli are made by wrapping pasta squares on the handle of a wooden spoon while pressing the pasta tubes against a gnocchi board to make ridges.

Learn how to make ravioli and other types of pasta

What to eat to lose weight

Eating a daily portion of French fries will eventually make you fat, and eating yogurt every day can keep you from gaining weight. This is one of the conclusions of a report published by researchers at Harvard University[1] which found that specific dietary and lifestyle factors are independently associated with long-term weight gain. The study found that a combination of these factors have aggregate effects. In essence, if French fries can make you fat and, independently, sugar-sweetened beverages can make you fat, the combination of French fries and sweet sodas will make you fatter than either one of them alone. The image above shows the pounds gained or avoided over four years for every additional serving per day of specific foods.

The research followed for twenty years 120,877 non-obese U.S. men and women, free of chronic disease from three different groups. Relationships between lifestyle factors and weight change were evaluated at 4-year intervals, with various adjustments made for age, baseline BMI, and lifestyle factors.

Overall, the participants gained 3.35 pounds, or 2.4% of their body weight, in each four-year interval. Over the 20 years of follow up, that amounted to almost 17 additional pounds. The data also revealed a strong weight-gain connection with certain foods, such as potatoes in various forms, sugar-sweetened beverages, unprocessed red meats, and processed meats. Some foods such as vegetables, whole grains, fruits, nuts and yogurt were inversely connected to weight gain, i.e., people who ate these foods gained less weight over time.

The study found that daily consumption of yogurt prevented 0.82 pounds of weight gain over each of the 4-year periods. Physical activity translated into 1.76 fewer pounds gained during each time period. Participants who slept less than six hours or more than eight hours per night gained more weight within each study period. Those who watched more television gained an average of 0.31 pounds for every hour of TV watched per day. Foods most strongly associated with weight gain every four years were potatoes, including fries (a 1.28-pound gain), sugar-sweetened beverages (1-pound gain), unprocessed red meats (0.95-pound gain), and processed meats (0.93-pound gain). Alcohol use was also associated with about a 0.41-pound gain per drink per day.

Each increased daily serving of potato chips alone was associated with a 1.69 pound-weight gain every four years. Potato chips are basically carbohydrates and fat with very little protein and almost no nutritional value. The Nutrition Label of Kirkland Kettle brand krinkle cut potato chips shows that one serving of 28 grams consists of approximately 9 chips. Eating those nine potato chips every day for four years results in a weight gain of 1.69 pounds.

One serving of potato chips

The results of the study demonstrate that the quality of the diet, i.e., the types of food and beverages that one consumes, is strongly linked to weight gain. One of your best strategies for losing weight is to increase your physical activity and reduce your consumption of potatoes and other simple carbohydrates such as white bread and sugar-sweetened drinks.

Learn more about weight loss.

[1] Dariush Mozaffarian, et al., Changes in Diet and Lifestyle and Long-Term Weight Gain in Women and Men, N Engl J Med 2011; 364:2392-2404 June 23, 2011

Diet Tips for Weight Loss

Obesity and risk of death [1]

Heart disease and cancer are the two largest causes of death, and obesity is responsible for increasing the occurrence of these two diseases.  Eating less to achieve a normal weight may help to lengthen your life by avoiding these two diseases. The graphs above show that the risk of death increases in direct relation to the Body Mass Index (BMI), which is a measure of obesity.

The practice of eating less is often called Calorie Restriction (CR).  CR is the most effective nutritional intervention for slowing aging and preventing chronic disease in experimental animals.  In humans, CR with adequate nutrition protects against abdominal obesity, diabetes, hypertension and cardiovascular diseases.  Data obtained from individuals practicing long-term CR show a reduction of metabolic and hormonal factors associated with increased cancer risk.[2]

All you have to do is eat right.  Your diet should have all the necessary nutrients and just enough calories to balance your level of activity.  To lose weight, you need to eat less than what your body needs so that your body fat can be burned off.  Here are some tips that can help you lose extra pounds and maintain a normal weight.

  • Keep records of the food you eat to increase awareness of your eating habits.
  • Weigh yourself regularly, at least once a week, and adjust your diet accordingly.
  • Exercise regularly.  Increased physical activity helps to burn calories.
  • Eat on a regular schedule and avoid snacking between meals.
  • Sit down to eat and eat slowly.  It takes about 15 minutes for your brain to feel the effect of food.
  • Chew food thoroughly before swallowing.
  • Eat from a small plate and avoid second helpings.
  • Leave the table after eating to avoid the temptation of extra food.
  • Store food out of sight.
  • Don’t shop when you’re hungry.
  • Plan social events around something besides food.
  • Drink water or low calorie beverages.  Sweet drinks can undermine your diet.
  • Limit consumption of fats, sweets, and alcohol.  Reduce dessert portion sizes.
  • Increase consumption of fruits, vegetables, whole grains, and legumes.

Use the diet calculator

[1] Adams KF. et al., Overweight, obesity, and mortality in a large prospective cohort of persons 50 to 71 years old, N Engl J Med. 2006 Aug 24;355(8):763-78,  PMID: 16926275

[2] Omodei D, Fontana L., Calorie restriction and prevention of age-associated chronic disease,
FEBS Lett. 2011 Mar 11, PMID: 21402069

Glycemic Index Diabetes Diet

Blood Glucose Response Curves

The glycemic index or glycaemic index is a measure of how the body reacts to dietary carbohydrates.  Carbohydrates that increase blood glucose quickly have a high glycemic index and they are called high GI foods.  Carbohydrates that break down slowly and produce a gradual rise in blood glucose are considered low GI foods.

The glycemic index was developed by Dr. D.J. Jenkins and his associates at the University of Toronto in an effort to find better diets for patients with diabetes.[1,2]  The glycemic index of a food is calculated based on the area under the two hour blood glucose response curve after the ingestion of a specific weight of carbohydrate (usually 50 grams). To obtain the GI, the area under the curve of the test food is divided by the area of the standard (glucose) and multiplied by 100.  An average GI value for a food may be calculated from data collected from several human subjects.

Diabetes is a metabolic disease that elevates the level of blood sugar, either because the body does not produce enough insulin, or because the cells of the body do not respond to the insulin that is produced.  Low GI foods help diabetics maintain better control of their blood sugar levels by reducing the rate at which sugars are absorbed by the body.

The difference between high GI and low GI carbohydrates is due to their chemical structure. Glucose, which is a simple sugar (high GI), is absorbed very rapidly and causes large increases in the blood sugar level.  Complex carbohydrates (low GI), on the other hand, need to be hydrolyzed before they can be converted into simpler carbohydrates that can be assimilated by the body.  Some of the complex carbohydrates are metabolized by the intestinal microflora into short chain fatty acids which do not elicit a glycemic response at all.  Thus, even with the same amount of total carbohydrate, a low GI meal produces fewer sugars that can increase the blood glucose level.

Learn more about carbohydrates

[1] Jenkins DJ, Wolever TM, Taylor RH, et al. Glycemic index of foods: a physiological basis for carbohydrate exchange. Am J Clin Nutr 1981;34:362–6.
[2] Foster-Powell K, Holt SH, Brand-Miller JC. International table of glycemic index and glycemic load values: 2002. Am J Clin Nutr 2002;76:5–56.

Vitamin E supplements may increase risk of stroke

Vitamin E is an essential nutrient found in spinach, watercress, mustard greens, and many green leafy vegetables. Good sources of Vitamin E are oily plant seeds such as peanuts and sunflower kernels. Vitamin E acts like an antioxidant, and a deficiency of this vitamin causes degeneration of nerve cells and fragility of red blood cells that is generally diagnosed as hemolytic anemia. The Recommended Dietary Allowance (RDA) for d-alpha-tocopherol, which is the biologically active form of Vitamin E, is 15 mg (22.5 IU) for adolescents and adults.

Many people take Vitamin E supplements because consumption of antioxidant vitamins may reduce the risk of certain cancers.  The supplement are usually sold in capsules of doses of 200, 400 and 1000 IU, but more is not better.  A recent study of 118,765 subjects split relatively evenly between the placebo and vitamin E groups found that overall, supplemental vitamin E had no effect on the risk for total stroke; however, when examining the stroke subtypes, there was a 22 percent increase in risk for hemorrhagic stroke (intracranial bleeding), and a 10 percent decrease in ischemic stroke (blockage of the blood supply by a clot).[1]

It is not necessary to take Vitamin E supplements if you eat a nutritious diet with plenty of leafy greens and some nuts.

Learn more about vitamins

[1] Markus Schürks, et al., Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials, BMJ 2010; 341:c5702