Category Archives: Nutrition in the News

Ask the Expert: Does being overweight really decrease mortality? No!

 The Expert: Dr. Walter Willett

Dr. Walter Willett

Fredrick John Stare Professor of Epidemiology and Nutrition, Departments of Nutrition and Epidemiology, and Chair, Department of Nutrition, Harvard School of Public Health

 

A recent JAMA study got major media attention when it claimed that grade 1 obesity (BMI 30-<35) was not associated with any greater mortality, than being normal weight (BMI 18.5-<25).   The authors also concluded that people who are up to 30 pounds overweight appear to have a lower risk of death than those who are within the normal BMI range for healthy weight. Many news articles or segments claimed that the study should come as a relief to those constantly struggling to lose weight because their extra pounds could actually be helping their health! Other sources have suggested that we need to re-organize our BMI ranges to reflect the study’s results, moving grade 1 obesity into a normal or healthy range. But our expert, HSPH’s Nutrition Department Chair, Dr. Walter Willett, explained that the study’s results are flawed and extremely misleading. In the following questions and responses, partially published by USAToday, Willett details the study’s weaknesses and provides advice to those who are overweight and possibly confused by these new findings. Read more about maintaining a healthy weight, what the BMI means, and explore ways to prevent obesity.

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Ask the expert: Sugary drinks and genetic risk for obesity

The Expert: Dr. Lu Qiqi

 

Assistant Professor in the Department of Nutrition, Harvard School of Public Health

We asked Dr. Lu Qi of the Harvard School of Public Health to explain the importance of considering genetic factors when approaching your diet. His recently published study suggests a link between sugary drinks and a genetic risk of obesity, and highlights the importance of gene-environment interaction in determining health outcomes. In the study of 33,097 individuals, those with a genetic predisposition to obesity were likely to be more adversely impacted by drinking sugary beverages; and the detrimental effects of sugary drink on body weight appeared to be amplified by high genetic risk. Read more about the study here.

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Ask the expert: Healthy fats

The Experts: Dr. Walter Willett and Amy Myrdal Miller

 

We asked Dr. Walter Willett of Harvard School of Public Health and Amy Myrdal Miller, M.S., R.D. of The Culinary Institute of America to explain why it’s time to end the “low fat is best” myth—and to provide ideas for how to use healthy fats in the home kitchen.

Dr. Walter Willett of HSPH and Amy Myrdal Miller, M.S., R.D. of The Culinary Institute of America (willett-and-myrdal-miller.jpg)

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Ask the expert: Coffee and health

The Expert: Dr. Rob van Dam

Dr. Rob van Dam

Assistant Professor in the Department of Nutrition, Harvard School of Public Health

The Summary

  • Drinking up to six cups a day of coffee is not associated with increased risk of death from any cause, or death from cancer or cardiovascular disease.
  • Some people may still want to consider avoiding coffee or switching to decaf, especially women who are pregnant,or people who have a hard time controlling their blood pressure or blood sugar.
  • It’s best to brew coffee with a paper filter,to remove a substance that causes increases in LDL cholesterol.
  • Coffee may have potential health benefits, but more research needs to be done.
  • Read more about coffee and tea compared to other beverages.

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Ask the expert: Omega-3 fatty acids

The Expert: Dr. Frank Sacks


Professor of Cardiovascular Disease Prevention, Department of Nutrition, Harvard School of Public Health

1. What are omega-3 fatty acids, and why should I make sure to include them in my diet?

Omega-3 fatty acids (also known as n-3 fatty acids) are polyunsaturated fatty acids that are essential nutrients for health. We need omega-3 fatty acids for numerous normal body functions, such as controlling blood clotting and building cell membranes in the brain, and since our bodies cannot make omega-3 fats, we must get them through food. Omega-3 fatty acids are also associated with many health benefits, including protection against heart disease and possibly stroke. New studies are identifying potential benefits for a wide range of conditions including cancer, inflammatory bowel disease, and other autoimmune diseases such as lupus and rheumatoid arthritis.

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Ask the expert: Vitamin D and chronic disease

The Expert: Dr. Edward Giovannucci

Dr. Edward Giovannucci

Professor of Nutrition and Epidemiology, Departments of Nutrition and Epidemiology, Harvard School of Public Health

1. There’s been a lot of news lately about vitamin D’s role in prevention of cancer, heart disease, and other chronic diseases. What do we know today—and what questions remain?

Vitamin D has a well-established role in maintaining calciumlevels in the body and in building strong bones. That’s why vitamin Ddeficiency could increase the risk of osteoporosis. In addition, elderly whodon’t get enough vitamin D have weaker muscles and are more prone to falls,which could further increase the risk of fractures.

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Ask the expert: Controlling your weight

 The Expert: Dr. Walter Willett

Dr. Walter Willett

Fredrick John Stare Professor of Epidemiology and Nutrition, Departments of Nutrition and Epidemiology, and Chair, Department of Nutrition, Harvard School of Public Health

 

1. How much control do we have over our body weight? And how much of our weight is controlled by our genes?

Genes do play a role in controlling our weight, but clearly they do not explain the huge increases in overweight and obesity we have seen in the last 30 years. We gain weight when our “calories in” (the food we eat) exceeds our “calories out” (the energy we burn). Given the genetic package we are born with, we can all improve our weight by paying attention to diet and getting regular physical activity, but some people will need to work harder than others to maintain a healthy weight. In other words, if we all eat and work out the same, we will not all look the same. Only a very small percentage of people have such a strong genetic predisposition that they will be obese no matter how hard they try. Even people who are genetically predisposed to obesity can reduce their risk of chronic disease by eating a healthful diet and staying active.

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