How Sitting Time Affects Appetite and Weight: Interview on the Research

What happens to appetite if you live a sedentary lifestyle? If extra activity can boost appetite in some circumstances, we might wish that if we sit all day and don’t burn up many calories, our bodies would recognize the need for fewer calories and reduce appetite.  Does it?

In this third and final portion of my interview with exercise researcher Barry Braun, PhD, we’ll get his insights on this.  Research is now looking at the health impact of how much time we spend sitting as a lifestyle choice separate from how much time we spend being physically active. Growing evidence suggests that too much sitting has effects beyond how many calories we burn.

If you’ve been working on reducing sitting time, please add your comments below with what has and has not worked for you.  You never know whom you’ll inspire!

Some thoughts on Dr. Braun’s comments….

Most of us have been on a slippery slope and not even noticed the changes in our lifestyle that have gradually added more and more sitting time to the day. Just a few small things: Do you remember having one or two phones in the house or on a college dorm floor, often standing as you talked on the phone? Do you remember when changing the TV channel meant getting up from your chair? When you walked down the hall at work to make copies? Make a list of examples from your home and work life, and I’ll bet you’ll be astounded.

Dr. Braun addressed the problems of how too much sitting time can lead to overeating 

Our bodies’ appetite regulation does not seem to have a feedback mechanism to communicate just how few calories we need when we sit all day.  When we’re burning far too few calories, we can’t rely on our natural hunger system as a guide for how much to eat. That adds one more stumbling block to reaching and maintaining a healthy weight.

Researchers are identifying other problems with too much extended sitting

Small controlled trials show increased markers of inflammation and insulin resistance with extended sitting.  Insulin resistance means you may have higher levels of insulin circulating throughout your body, which is a concern since managing blood sugar is not insulin’s only effect.  Excess insulin also seems to stimulate growth and development of cancer cells.  Short-term intervention trials have shown decreased insulin function or elevated insulin levels not only in  overweight, middle aged adults, a group more likely to be developing insulin resistance, but even in young, fit men and women of normal weight.

Population studies suggest that excess time spent sitting each day may be linked to increased risk of heart disease, type 2 diabetes and metabolic syndrome, and risk of some cancers may rise as well. You’ll find more details about some of these findings in my review, Extended Sitting: Why researchers see health impact & What you can do.

Three strategies to implement now

• Switch 10 or 20 minutes that you now use to relax or unwind in a sedentary mode such as TV, crossword puzzles, or flipping through magazines to relaxing with some moderate activity such as taking a walk, turning on music and dancing or playing hide-and-seek with your kids (or the neighbors’).
• Look for 30 minutes of time you now spend sitting and stand instead. You can get some ideas for putting this in action from my earlier post devoted to this subject.
• Insert breaks of two to five minutes into periods of extended sitting at home or at work. Check the Resources below for ideas.

Let’s talk! Please comment below with what you’ve been doing and what you’re going to try.

Resources

Check Page 3 for specific ideas of how to Sit Less, Move More from the National Heart Foundation of Australia. (2011)

For some ideas on how to work more activity into your day, check Healthy Moves a Couch Potato Can Love.  AICR eNews. May 6, 2010.

Extended Sitting: Why researchers see health impact & What you can do. My review from November 10, 2011.

References

Granados, K et al.  Appetite regulation in response to sitting and energy imbalance. Appl Physiol Nutr Metab. 2012 Apr;37(2):323-33.

Dunstan, DW et al. Breaking up prolonged sitting reduces postprandial glucose and insulin responses. Diabetes Care. 2012 May;35(5):976-83.

Stephens, BR et al. Effects of 1 day of inactivity on insulin action in healthy men and women: interaction with energy intake.  Metabolism. 2011 Jul;60(7):941-9.

Hamilton, MT et al. Role of Low Energy Expenditure and Sitting in Obesity, Metabolic Syndrome, Type 2 Diabetes, and Cardiovascular Disease. Diabetes 56:2655–2667, 2007.