New AICR/WCRF Report On Growing Obesity Epidemic Released

By Author Anne McTiernan

The American Institute for Cancer Research (AICR) recently launched a new report as part of its Continuous Update Project (CUP) titled – Diet, Nutrition, and Physical Activity: Energy Balance and Body Fatness, which highlights the wide prevalence and causes of obesity. Dr. Anne McTiernan, a Research Professor in Public Health Sciences Division at Fred Hutchinson Cancer Research Center, is one of AICR expert panel members. Her research also includes a specific focus on mechanisms that are known to link obesity and sedentary lifestyle to cancer. Here she outlines the major findings of the report and their significance in a Q&A session.

What in your opinion are the most important findings of the new CUP report? The first key takeaway to me is the assembling of strong evidence that obesity can be prevented through simple lifestyle changes. The report offers clear evidence that physical activity and high-fiber diets altogether reduce the risk of weight gain, having overweight or obesity. On the flip side, it gives evidence that consuming sugar-sweetened drinks, eating fast-foods, and spending greater screen time increase the risk of weight gain, overweight or obesity.

On diet specifically, the report shows that following a “Mediterranean-type” diet (high in vegetables, fruits, and fish, lower in meat and dairy, and rich in olive oil) can reduce risk while a more “Western-type” diet (high in sugars, meats, and fat) can increase the risk of weight gain.

Thirdly, there are findings on breastfeeding, with the report furnishing very strong evidence that infants that are breastfed have a lower risk of having overweight or obesity in childhood and also suggesting that breastfeeding may reduce chances of weight gain, overweight, and obesity in mothers.

Relevance to cancer: Can you suggest how everyday Americans can embrace the findings of the report through actions on diet and activity, especially in this festive season? Resolve is perhaps the most important aspect of any regimen for checking weight gain. Most American adults gain one to two pounds a year. Over time, that adds up significantly. The coming holiday season is a prime time for weight gain, so a good time to resolve to makes changes to day-to-day habits. Some simple things: avoid sugar-sweetened drinks and desserts, including those at holiday parties.

Try to eat more meals at home, or meals prepared at home, in order to avoid going to fast food restaurants. If a fast-food restaurant visit cannot be avoided, one should try to maximize sticking to salads, a chicken sandwich, or an item under 350 calories (ask for the calorie menu if it is not posted). For a drink at a restaurant, stick to water, coffee (unsweetened), or tea (also unsweetened). Add more vegetables and fruits to your daily menu.

And although the holiday season is a great time for sitting together to watch a film or catch up on family gossips, try to get in at least 30 minutes a day of moderate activity. Even going out on a walk with your family can be very rewarding and helps cut down on sedentary time.

The holiday season can also be a time to take stock of what you have done on weight loss and how effective those have been. For people whose weight falls in the overweight or obese category, I would suggest asking specialists for help with selecting weight loss programs. There are online and in-person programs that anyone can use. Your doctor may be able to refer you to medical options. There are also options available through certain organizations. For instance, the YMCA has a diabetes prevention program for which people having overweight and obesity may qualify to participate.

How can policymakers help when it comes to combating growing weight gain and obesity epidemic in the country?Anything that can promote healthy diets and an increase in physical activity will be helpful. This may include developing and implementing policies that curtail the availability of sugar-sweetened drinks, increase the availability of fresh vegetables and fruits, and improve access to safe areas for physical activity for children and adults (both men and women). Supporting work environments for mothers to breastfeed long-term will help reduce excess weight gain in infants and toddlers.

In your research, you have focused on the links between weight, physical activity, and cancer. Can you sum up the findings from the report that relate to those linkages? In our clinical trials, we have found that both diet and exercise help with weight loss. The key to weight loss was reducing calories and monitoring food intake. We found that women who kept careful track of what they ate by writing it down in a journal lost more weight than women who did not keep a tab on their food intake. Reducing fat intake, eating at regular intervals, and not skipping meals were found to correspond with weight loss. Following a moderate-intensity program of 45 minutes a day of walking, biking, or gym (e.g. treadmill, elliptical) also hastened weight loss.

The overall best advice for cancer prevention is to keep weight in the normal range, lose weight if you already have overweight or obesity, and stick to an active lifestyle.

We also found that even small amounts of weight loss can significantly lower the body’s production of hormones and proteins, and lower inflammation, all of which are related to cancer risk. Losing just 5 to 10 percent of initial weight lowers blood estrogen by about one-fifth (20 percent). This percentage of weight loss can lower inflammation in the blood by almost half and can lower insulin by a quarter. We found that exercise can also bring some of these same positive effects, but the net gain in these concrete deliverables was lower than in the case of weight loss through diet management.

The overall best advice for cancer prevention is to keep weight in the normal range, lose weight if you already have overweight or obesity, and stick to an active lifestyle.

 AICR offers a free, online 12-week program called the New American Plate Challenge that helps you eat a cancer-protective diet, move more and adapt other habits for a more overall healthful lifestyle. Join now!