why weight management is more difficult in middle age and older

Weight Management in Middle Age & Beyond: A Whole New World

If you’re over 40, does it seem as if it’s a lot harder to lose weight, and a lot easier to gain it, than it was in your 20’s? It’s not your imagination, according to Steven Heymsfield, MD, Executive Director of the Pennington Biomedical Research Center. He says that if you don’t make any changes in your eating or physical activity habits as you get older, you’re going to gain weight.

Is there anything that can be done about this? In the first part of my video interview with Dr. Heymsfield, who is renowned for his weight and calorie balance research, he explained why you don’t get the pound of weight loss you may be expecting each time you add up a total of 3500 calories’ worth of cut-backs in eating or boosts in activity. In this section of our conversation, he addresses this question of the increasing difficulty of weight management in middle age.  Following the interview, read on for what you can do about it.

Eating the Same and Gaining Weight

Research shows that adults’ calorie needs generally decrease as they get older.  In Dr. Heymsfield’s presentation at the conference where I interviewed him, he showed a 50-year-old woman burning approximately 9 percent fewer calories per day than at age 20.  And from age 50 to 70, calorie needs drop even lower.  If other factors remain the same, a woman at 70 is burning about 15 percent fewer calories per day than she did at age 20.

This finding is precisely what we’d expect from the currently recommended formula (Mifflin-St. Jeor) health professionals use to estimate people’s calorie needs. Based on that formula, we expect resting metabolic rate (calories needed just to keep body functions going without any activity) in both men and women to slow down by about 150 calories a day from age 20 to age 50.  From age 50 to age 70, metabolism (resting metabolic rate) is expected to decrease an additional 100 calories per day (a total of about 250 calories less each day than at age 20).

This resting metabolic rate accounts for a major portion of total calories burned each day for most people, so it’s very important.  Overall, with other influences factored in, compared to the calories they burned at age 20:

  • Most adults burn about 200 fewer calories each day at age 50
  • And 320 to 350 fewer calories each day at age 70. 
  • That is assuming physical activity level remains the same….We’ll look at that in just a moment.*

This decrease in basic calorie needs is why Dr. Heymsfield said in our interview that if you eat the same as you get older, you’ll most likely gain weight.  How much weight? This is another situation in which people often pull out the old “every 3500 calories equals a pound of weight” rule – but remember the first part of my interview with Dr. Heymsfield in which he explains that such a statement is now outdated.  Today’s Dynamic Model predicts changes in weight based on increases or decreases in calorie consumption.  It can’t necessarily be assumed that the expected 150-calorie-per-day decrease in metabolic rate we face at age 50 will have precisely the same effect on weight as increasing calorie consumption.  But here’s what today’s Dynamic Model predicts for how consuming an extra 150 calories a day affects weight for someone of average height and a currently healthy weight:

  • For a 20-year-old man, weight gain of about 2 pounds a year
  • For a 50-year-old man, weight gain of about 2.7 pounds a year
  • For a 20-year-old woman, weight gain of about 3 pounds a year
  • For a 50-year-old woman, weight gain of about 3.5 pounds a year

What’s Behind the Typical Middle-Aged Weight Gain?

The weight gain that is so typical as people approach and pass through middle age stems from several different influences.

♦ The body is burning fewer calories because of this slow down in metabolic rate noted above. Scientists don’t completely understand how or why this happens.  During these years, even at the same weight, body composition tends to change, with more body fat (especially around the abdomen) and often a decreased amount of lean weight (muscle and other tissue).  So is it the decreased metabolic rate that leads to the typical changes in body composition, or vice versa?  A review of research on this question concluded that changes in body composition could not completely account for the drop in resting metabolic rate, so though we don’t understand what, something more seems to be part of this metabolic change.

Decreased physical activity is another important part of adult weight gain. Some evidence suggests that perhaps physically active people might not face as much of a metabolic slow-down as sedentary people. Still, no matter what your metabolic rate, more sitting and less moving simply burns fewer calories. Especially for people who weren’t all that active to begin with, changes in activity level can fly under our radar as we run around less with our children, spend more time driving, do more sitting at work, or get so busy that we drop out of sports leagues or exercise groups in which we once participated.  Get-togethers with friends often become more about sitting and eating than walking places and doing things. We spend time watching sports instead of playing them.

  Hormonal changes, such as the drop in estrogen shortly before and during menopause do not seem to cause weight gain itself, but these hormonal changes are associated with an increase in total body fat and an increase in abdominal fat.

 What’s the Take-Home Message?

1. Step up your activity level.

As Dr. Heymsfield notes in our interview, the drop in calorie-burning that occurs as we get older can be counter-balanced by the increase in calories burned when someone increases their current amount of physical activity to the next level.  Researchers and health professionals often categorize physical activity level as sedentary, low-active, active or very active.

~A sedentary woman who becomes low-active burns about 200-230 more calories each day.

~A low-active woman who becomes active burns about 210-270 more calories each day.

~An active woman who becomes very active burns 300-325 more calories each day.

~Men show similar, though often slightly greater, increases in calories burned each day with each of these transitions.

~The same change in physical activity will produce a greater increase in calories burned in someone who weighs more than in someone who weighs less.

Notice that these increases in calories burned when activity increases are about the same as the decrease in calories burned as we get older.

 However, a Key Point: Don’t expect dramatic changes in calorie balance from doing a little gardening once a week, or taking a 30-minute walk three days a week.

This system of categorizing activity researchers use when studying exercise effects is based on what’s called a PAL (physical activity level).  Every bit of activity adds up – and provides important health benefits totally outside of impact on weight. But the changes in physical activity noted above that are comparable to an age-related drop in metabolism mean adding each day an extra hour of moderate physical activity (like walking at a brisk pace) or two extra hours of light activity such as light gardening or light housework.

This boost in activity could come in several  10- or 15-minute blocks of activity if that’s easier. But if you don’t find a way to add that much extra activity, then avoiding weight gain means you need to eat fewer calories as you get older.

2. Cut calories, not nutrition.

The difference of about 200 to 400 calories a day between what you burn at age 50 or 70, respectively, compared to what you burned at age 20 does not mean you need to go hungry or follow a strict diet to stay in the “energy balance” (the balance between calories you consume and calories you burn) that Dr. Heymsfield
discussed. Here are a few examples of calorie-cutting changes you can make. Two to four of these a day would add up to balance out the drop in metabolism as we get older.

~Rethink how often you include foods with more calories than nutrients. If you’ve been having more than one of such calorie-dense treats each day, try choosing one a day, saving another option for the next day. If you’re hungry, choose an apple instead of a snack bag of chips to cut fat and add fiber.   (minus 50-100 calories)

~Reduce treat portions. If you’re a chocolate lover, indulge by slowly savoring a wrapped one-ounce or less gourmet chocolate or portioning out four chocolate kisses or a coffee scoop (two tablespoons) of chocolate chips.  If you can’t do without French fries, drop your usual order one size (or eat only half of what comes on most restaurant plates). (minus 100-170 calories)

~ Switch 12 ounces of a sugar-sweetened soft drink or bottled tea to water or unsweetened tea.  (minus 130-150 calories)

~If you’ve been enjoying a couple glasses of wine each night, stop at one instead. (minus 90-125 calories)

~Don’t give up grains, but don’t overdo just because whole grains are so healthful. Instead of filling a bowl with cereal, stick to one or one-and-a-half of the label’s serving size.  Enjoy a half- to one-cup portion of pasta or rice, not the platter we’ve come to think is a serving. (minus 50 to 150 calories

There are lots of ways to cut calories without going hungry and without giving up nutrition. In fact, smart calorie-cutting strategies can even help you get more nutrients. For specific ideas on how to accomplish this, check this update that includes an interview with Barbara Rolls, PhD, RD.

3. Don’t count on supplements.

The Internet, magazines and TV infomercials are full of supplements that claim to be able to rev up your metabolic rate. On TV you’ll usually see in small print, “Results described are not typical”, but store displays aren’t as limited by rules about saying what can’t be proven.

Since ephedra was banned from supplements because of the health risks it posed, most supplements today that claim to be calorie-burners contain a combination of bitter orange (Citrus aurantium) and caffeine. There is some evidence that bitter orange may increase basic calorie-burning rate, but unfortunately, it is not risk-free.  One review of research on its safety suggests that it may be reasonably safe, but studies are only short-term, so we have no sound data on long-term use (which of course is what would be needed to counteract the drop in metabolic rate with age that does not go away!).  According to the Natural Medicines Comprehensive Database (considered the gold-standard reference on supplements and botanicals),  bitter orange-containing products are likely to have the same or similar potential adverse stimulant effects as ephedra, and have been linked to high blood pressure and heart-related incidents in otherwise healthy patients who have taken bitter orange extract alone or with other stimulants.

 

Check back for the next portion of my interview with Dr. Heymsfield, in which he talks more specifically about what we can expect from physical activity to help with weight management.  He says the results of cutting calorie consumption and boosting calories burned in activity are not the same. You’ll want to hear about this!

 

Resources

For more on the concept of Energy Balance”, check this information from the National Heart, Lung and Blood Institute (part of the federal NIH). You’ll find some simplified charts illustrating how calorie needs change with age and physical activity.

For some specific examples of eating patterns showing how just a few basic changes in food choices add up to balance the drop in calorie needs as we get older, compare the eating patterns in Appendices 7, 8, 9  and 10 from the Dietary Guidelines for Americans, 2010.

References

Frankenfield, D et al. Comparison of Predictive Equations for Resting Metabolic Rate in Healthy Nonobese and Obese Adults: A Systematic Review. J Acad Nutr Dietetics. 2012; 112(9): 1415-1420.

Thomas DM et al. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule.  International Journal of Obesity, advance online publication  April 30,2013. doi: 10.1038/ijo.2013.51

St-Onge MP and Gallagher D. Body composition changes with aging: the cause or the result of alterations in metabolic rate and macronutrient oxidation? Nutrition. 2010 Feb; 26(2):152-5.

Van Pelt RE, et al. Regular exercise and the age-related decline in resting metabolic rate in women. J Clin Endocrinol Metab. 1997 Oct;82(10):3208-12.

 

5 Comments

  1. Abigail Janes on May 13, 2013 at 6:51 pm

    Thank you for all your info! This was exactly what I was looking for. Keep it up!

  2. Ann on May 13, 2013 at 10:10 pm

    thanks

    • Karen on May 15, 2013 at 11:43 am

      Glad you found the information here of help, Ann. Check back for the next two parts of my conversation with Dr. Heymsfield. And if you haven’t already, I hope you’ll subscribe to Smart Bytes by RSS feed or email so you can stay updated and join in future discussions.

  3. Tehachapi News on May 14, 2013 at 11:53 am

    Great info. Lucky me I discovered your site by accident (stumbleupon). I’ve book-marked it for later!

  4. Heidi Diller on December 14, 2013 at 7:27 pm

    Wondering if Dr.Heymsfieid addressed the changes that often come with age and menopause such as insulin resistance in many women and its role in weight gain. Or maybe you have addressed this topic in other videos? I am more active now at 50 than I was in my 20s. And i am finding the weight gain a mystery and I can only lose weight now when I follow a lower glycemic diet. I think there is more to weight management in older age than increasing activity and also should include the topic of hormone balance.

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Meet the author/educator

Karen Collins
MS, RDN, CDN, FAND

I Take Nutrition Science From Daunting to Doable.™

As a registered dietitian nutritionist, one of the most frequent complaints I hear from people — including health professionals — is that they are overwhelmed by the volume of sometimes-conflicting nutrition information.

I believe that when you turn nutrition from daunting to doable, you can transform people's lives.

Accurately translating nutrition science takes training, time and practice. Dietitians have the essential training and knowledge, but there’s only so much time in a day. I delight in helping them conquer “nutrition overwhelm” so they can feel capable and confident as they help others thrive.

I'm a speaker, writer, and nutrition consultant ... and I welcome you to share or comment on posts as part of this community!

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