Author Archives: The Nutrition Source

Walking and bicycling your way to health

cyclingWalking is an ideal exercise for many people—it doesn’t require any special equipment, can be done any time, any place, and it is generally safe. Also, many studies – including the Nurses’ Health Study, (1, 2) Health Professionals Follow-up Study, (3) Women’s Health Study, (4)Harvard Alumni Health Study, (5) National Health Interview Survey, (6) Women’s Health Initiative, (7) Honolulu Heart Program, (8) Black Women’s Health Study, (9) and others (10, 11) – have demonstrated that this simple form of exercise substantially reduces the chances of developing heart disease, stroke, and diabetes in different populations.

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Make exercise a daily habit – 10 tips

Whether you’re looking for motivation to start exercising, or are interested in changing up your current routine, here are 10 tips for making exercise a daily habit. Staying_active_shoes

  1. Piece your workout together. You don’t need to get all your exercise at one time. Ten minutes morning, noon, and night can give much of the same benefit as 30 minutes all at once.
  2. Exercise with a friend. Finding a workout partner can help keep you on track and motivate you to get out the door. Continue reading

Misguided Moves Thwart Healthier School Lunch

Congress Scraps Limits on French Fries, Keeps Pizza a Vegetable


No one would mistake French fries and pizza for a healthy meal. Yet Congress has overturned a plan that would limit French fries in school lunch. And it’s scrapped or stalled other healthy menu changes that would boost vegetables and lower salt.

The final version of an agricultural spending bill, passed by Congress and signed into law in late November 2011, has watered down a comprehensive U.S. Department of Agriculture (USDA) proposal for improving school lunches. The USDA’s original plan was based on sound science and could have helped turn around this country’s obesity and diabetes epidemics. But the guidelines came under fire from food industry lobbyists, among them, potato growers, frozen pizza makers that supply schools, and the salt industry.

The USDA’s proposal would have capped the amount of potatoes and starchy vegetables that school lunches could serve at one cup per week—the equivalent of a medium baked potato—and promoted a wider variety of vegetables, especially dark green and orange varieties, such as broccoli, spinach, and carrots. (1) It would have also changed the serving size for tomato paste, bumping it up from 2 tablespoons to ½ cup—a change that meant a pizza slice, with its dab of tomato paste, could no longer count towards the school lunch vegetable requirement. The changes were part of a long-awaited overhaul of the nutrition standards in U.S. school meal programs, based on recommendations from an expert panel at the Institute of Medicine (IOM). (2)

Congress’ new wording in the funding bill scrapped the weekly limit on starchy vegetables. It also spelled out that the USDA must stick with the status quo on tomato products, meaning that the tomato paste on a pizza slice can still count as a vegetable.

These changes have been met with harsh criticism from nutrition and public health advocates, and with good reason: Potatoes, which are high in fast-digested carbohydrate, seem to be a particular culprit for weight gain and diabetes. (3, 4) Children eat plenty of potatoes but don’t eat enough dark green and orange vegetables. (2) Continuing to allow unlimited potatoes and pizza sauce to count as vegetables won’t do much to achieve the IOM’s goal of boosting children’s vegetable intake, and ultimately, improving their health.

In addition to backpedaling on potatoes and pizza, Congress put the brakes on planned sodium reductions in school lunch, “until the [USDA] Secretary certifies that the Department has reviewed and evaluated relevant scientific studies and data relevant to the relationship of sodium reductions to human health.” Yet this hesitancy does not make scientific sense: More than 90 percent of school children already get more than recommended amounts of sodium each day. (2) Though the salt industry lobbies mightily to the contrary, there’s ample evidence that high sodium intakes contribute to high blood pressure, even in children and teens, (5) and to heart disease in adults, and that curbing sodium lowers cardiovascular disease and death rates over the long term.

Congress also pushed back on the USDA’s plan to require more whole grains, saying that the USDA needs to define what whole grains are before it can issue such a requirement.

In a statement to the Associated Press, a USDA spokeswoman, Courtney Rowe, said the agency will still work to improve the nutritional quality of school lunch:  “While it’s unfortunate that some members of Congress continue to put special interests ahead of the health of America’s children, USDA remains committed to practical, science-based standards for school meals.”


1.U.S. Department of Agriculture. Nutrition Standards in the National School Lunch and School Breakfast Programs: A Proposed Rule by the Food and Nutrition Service on 01/13/2011. Federal Register. 2011;76:2494–2570.

2. Institute of Medicine. School Meals: Building Blocks for Healthy Children. Washington, D.C.: National Academies Press; 2009.

3. Halton TL, Willett WC, Liu S, Manson JE, Stampfer MJ, Hu FB. Potato and french fry consumption and risk of type 2 diabetes in women. Am J Clin Nutr. 2006;83:284-90.

4. Mozaffarian D, Hao T, Rimm EB, Willett WC, Hu FB. Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med. 2011;364:2392-404.

5. He FJ, Marrero NM, MacGregor GA. Salt and blood pressure in children and adolescents. J Hum Hypertens. 2008; 22:4–11.

Too much salt, too little potassium, increases risk of death

Here’s yet another reason why you should eat more fruits and vegetables and cut back on processed foods: A large new study finds that people who eat high sodium, low potassium diets have a higher risk of dying from a heart attack or from any saltcause. The study, which appears in the July 11, 2011 issue of Archives of Internal Medicine, (1) bolsters the already-substantial evidence that high salt diets have negative effects on health. (2-4) And it highlights a key dietary change people can make to lower their risk: Eat more fresh vegetables and fruits, which are naturally high in potassium and low in sodium—and eat less bread, cheese, and processed meat, since these and other processed foods are high in sodium and low in potassium.

“Much confusion was caused by a recent, widely quoted report concluding that lower salt intakes were associated with higher risk of cardiovascular disease,” says Dr. Walter Willett, chair of the Dept. of Nutrition at Harvard School of Public Health. “This new study is much larger and controlled for key factors that were ignored in the previous report.”

Sodium and potassium have opposite effects on heart health: High salt intakes increase blood pressure, ultimately leading to heart disease; high potassium intakes can help relax blood vessels and decrease blood pressure. Our bodies need far more potassium each day than sodium, and most Americans should limit their sodium intake to 1,500 milligrams per day, the amount in about two-thirds of a teaspoon of table salt. (5) But the typical US diet—heavy on the processed foods, light on the produce—is just the opposite: Americans average about 3,300 milligrams of sodium per day, about 75 percent of which comes from processed foods, while only getting about 2,900 milligrams of potassium each day. (3,6)

The newest study, which is based on diet reports from participants in the National Health and Nutrition Examination Survey, followed just over 12,000 men and women for an average of 15 years. Sodium intakes averaged about 4,300 milligrams per day in men and 2,900 milligrams a day in women.(1) Potassium intakes averaged a good bit lower (3,400 milligrams and 2,400 milligrams), and substantially lower than the 4,700 milligrams per day that the US government recommends. (7)

People with the highest sodium intakes had a 20 percent higher risk of death from any cause than people with the lowest sodium intakes. People with the highest potassium intakes had a 20 percent lower risk of dying than people with the lowest intakes. But what may be even more important for health is the relationship of sodium to potassium in the diet: People with the highest ratio of sodium to potassium in their diets had double the risk of dying of a heart attack than people with the lowest ratio, and they had a 50 percent higher risk of death from any cause. (1)

Given that processed foods are responsible for much of people’s sodium intake in the US and Europe, governments have started working with the food industry to lower sodium levels. Finland and the United Kingdom have led successful sodium reduction efforts, (8) and in the US, the Institute of Medicine has recommended that the Food and Drug Administration regulate the amount of salt in commercially prepared food—a recommendation that’s likely to receive pushback from the salt industry, which continues to argue that salt has little influence on blood pressure. (9) Encouragingly, some manufacturers have voluntarily agreed to cut back on sodium by 20 percent over the next five years, as part of New York City’s National Salt Reduction Initiative. (10) Walmart has also pledged to cut back on sodium and decrease the prices of fresh produce in its stores. It remains to be seen whether the food industry will be able to deliver on these pledges. (Campbell Soup reportedly announced in early July 2011 that it was raising the salt levels in some of its soups, blaming its previous salt reduction efforts—and the resulting changes in product taste—for sagging sales.

It could take a decade for any US regulatory changes to take effect. In the meantime, there are steps that consumers can take to curb sodium intake and boost potassium.


1. Yang Q, Liu T, Kuklina EV, et al. Sodium and Potassium Intake and Mortality Among US Adults: Prospective Data From the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2011;171:1183–91.

2. Strazzullo P, D’Elia L, Kandala NB, Cappuccio FP. Salt intake, stroke, and cardiovascular disease: meta-analysis of prospective studies. BMJ. 2009;339:b4567.

3. Brown IJ, Tzoulaki I, Candeias V, Elliott P. Salt intakes around the world: implications for public health. Int J Epidemiol. 2009;38:791–813.

4. World Cancer Research Fund, American Institute for Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective. London; 2007.

5. Application of lower sodium intake recommendations to adults—United States, 1999–2006. MMWR Morb Mortal Wkly Rep. 2009;58:281–3.

6. Dietary Guidelines for Americans Scientific Advisory Committee. 2010. Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, to the Secretary of Agriculture and the Secretary of Health and Human Service.

7. Institute of Medicine. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, D.C.: National Academies Press; 2005.

8. He FJ, MacGregor GA. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. J Hum Hypertens. 2009;23:363–84.

9. Institute of Medicine. Strategies to Reduce Sodium Intake. Washington, D.C.: National Academies Press; 2010.

10. National Salt Reduction Initiative – Statement of Commitment by Health Organizations and Public Agencies. 2011.