Weight Loss: You're Still Accountable
Just last month a weight-loss study was published in the journal Obesity Research & Clinical Practice. Although the media was certainly all over it:
- "Weight Loss was Easier in the '80s." Food World News.1
- "Why It Was Easier to Be Skinny in the 1980s." The Atlantic.2
- "It's harder to be thin than it was in the '80s." AOL.3
- "Not mom's weight loss: For millennials, more than diet and exercise at play." CNN.4
I'm not sure it actually means quite what they think it does--or for that matter, that it even means what the researchers think it means. Everyone seems to want to treat the study as a "get out of jail free" card--saying that weight gain is really out of your hands. As much as I sympathize with that concept, I don't think it's true. And I don't think it does anyone any favors to promote the study as such. In any case, since weight-loss is such a big deal for so many people, what with 2/3 of the population either overweight or obese, it's probably worth taking a look at to see what all the fuss is about.
The purpose of the study was to determine whether the relationship between obesity and caloric intake, macronutrient intake, and physical activity has changed over time.5 Not surprisingly, it has. While caloric intake has indeed gone up over the years, the study also concluded that leisure time physical activity had also gone up (more on that later) and that the net result was that the body mass index (BMI) of people had gone up more than expected. The study concluded that factors other than diet and physical activity may be contributing to the increase in BMI over time. The media announced this as proof that the old maxim, "Calories in--calories out," no longer applies to losing weight. Actually, they're wrong; it still does.
We've discussed this many times before. Ultimately, your weight is determined by calories in VS calories out. If you burn more calories than you take in, you lose weight. If you take in more calories than you burn, then you gain weight. That said, there are indeed factors that can affect the terms of that equation--not the equation itself--but its terms. For example: muscle burns calories. There may be some debate as to how many calories it burns, but the simple fact is that muscles burn calories, even when they are not being exercised--simply by existing. Fat, on the other hand does not burn calories; it stores them. In fact, fat is designed to be a storage system for calories. That's its purpose. The bottom line is that the more muscle you have, the more calories you will burn. Even if you eat the exact same food as a person with more fat and exercise the exact same amount, you will burn more calories on any given day. As I said, the equation still applies: it's still calories in VS calories out. But if you've done the work to build the muscle, you're rewarded with more calories burned down the road with no extra effort required.
Nevertheless, the media saw things differently. They saw it as a chance to give their readers a free pass. As they said, "You diet and exercise, but can't shed the pounds. You can at least take comfort in a new study that suggests many other factors, including stress and pollution, could be conspiring to make weight loss harder today than a few decades ago."
Now that's the media's interpretation, but what exactly did the study say?
In fact, the study looked at dietary data from 36,377 U.S. adults from the National Health and Nutrition Survey (NHANES) conducted between 1971 and 2008. Physical activity frequency data was only available in 14,419 adults between 1988 and 2006--again based on survey data, which is probably significant, since people tend to overestimate their exercise levels as well as underestimate their consumption levels. In any case, statistical models were used to examine if the association between total caloric intake, the percent of dietary macronutrient intake, and physical activity was different over time as it relates to the body mass index (BMI) of the study's participants. Note: a BMI of 18.5 to 24.9 is considered normal weight, 25 to 29.9 is overweight, and 30 or more is obese.
The researchers found that between 1971 and 2008:
- Total caloric intake and carbohydrate intake increased 10-14%, and fat and protein intake decreased 5-9%. In other words, not surprisingly, people are eating more. Again, these numbers may be underestimating the amounts being increased. Remember, it's based on a survey and relies on people accurately remembering and reporting what they ate. As already mentioned, historically, they tend to underestimate what they have eaten.
- Between 1988 and 2006, the frequency of leisure time physical activity increased 47-120%. I have a real problem with these numbers as this finding would seem to contradict the results of numerous other studies. In fact, it seems directly at odds with the amount of time people are now spending sitting in front of their TV's or computers. (More on this later.)
- A person in 2006 would have a BMI that was 2.3 points higher than someone in 1988 who consumed the same number of calories and exercised the same amount.
In other words, according to the researchers, factors other than diet and physical activity might be contributing to the increase in BMI over time.
"I didn't expect to see this finding," said Jennifer L. Kuk, associate professor of kinesiology and health science at York University in Toronto, who led the research. According to Kuk, obesity rates worldwide have been climbing since the 1980s, and people have always thought it was because we are eating more and exercising less. Now, the study itself made no attempt to investigate what those other "factors" might be. Nevertheless, other research points a finger at numerous factors that have been linked to obesity and that have changed over the last several decades. These include:
- Endocrine disrupting chemicals such as PBDE flame retardant and BPA in the environment. These chemicals have been steadily increasing in levels in humans and have been implicated in contributing to obesity in humans. Other chemicals known to function as human endocrine disruptors include heavy metals, solvents, organophosphates, phthalates, dioxins, and pesticides. And there are plenty of those in the environment.
- We take more medications associated with weight gain than we used to, such as antidepressants.6 In fact, the number of patient visits that result in antipsychotic prescriptions has gone up 600% in the last 20 years.
- Over the last 40 years, there has been a dramatic change in childbearing patterns. Women are waiting longer to have children. The mean age of mothers has gone up about 25% in the last half century. Why is this important? Because animal models7, 8, 9 and epidemiologic investigations10, 11, 12 have demonstrated a direct and independent association between maternal age and obesity in offspring. The key here seems to be that the older the mother, the more predisposed the offspring is to having a higher ratio of white fat to brown fat. As we will discuss in a moment, this slows down the body's ability to burn fat calories for energy.
- We increasingly live in climate-controlled worlds that don't require us to burn calories to maintain our body temperature. It also reduces brown fat levels in the body as the body no longer needs to burn fat to generate heat--a process known as brown fat thermogenesis.
As we have discussed in previous newsletters, brown fat is located around the shoulders, neck, spine, and around major organs and blood vessels. It comprises about five percent of your total fat levels and gets its color from the large number of mitochondria (energy producing organelles) it contains. Brown fat specializes in burning white fat (the fat you want to get rid of) for heat energy. It's the metabolic activity (or inactivity) of brown fat that makes it easy (or difficult) to lose weight. Back when I first started writing on this topic, just over a quarter of a century ago (my how time flies), I wrote about how scientists had recently discovered Brown Fat Thermogenesis, a metabolic function in which regulator cells (brown fat cells) burn white fat cells to produce heat. Each brown fat cell can burn as much as 20 times its own weight in stored white fat. The trick is that brown fat and white fat have completely different origins. Brown fat is derived from muscle, as confirmed by recent studies.13 Go on a starvation diet with no exercise, and you lose not only muscle, but also brown fat. On the other hand, if you exercise, you increase the amount of muscle and brown fat -- improving your ability to burn off calories.
- We're sleeping less than we used to. According to a 2013 Gallup poll, about 40 percent of Americans now get less than the recommended minimum of seven hours of sleep per night.14 In fact, as the study itself noted, we're now sleeping about 3 hours less a night than we did in 1920. Sleep debt exerts profound effects on metabolic hormones. These changes favor not only increased food intake and energy storage, but also potentially the development of diabetes and heart disease.15, 16 Additionally, there appears to be some scientific evidence that lack of sleep increases production of the hormone ghrelin, whose primary function is to increase appetite.
- Overall stress levels have steadily increased over the last 50 years. Not only does increased stress cut into sleep time, which as we've already seen increases fat storage, but it also increases production of cortisol and other stress hormones that tell the body to store fat.
- The use of antibiotics in our food supply has increased exponentially over the last several decades. It is now implicated as one of the primary factors in the incredibly rapid growth of antibiotic resistant bacteria--leading to what is now being called the end of the age of antibiotics. And as bad as that is, there's another problem with antibiotics in the food chain: a number of studies have found that antibiotics encourage the accumulation of body fat.17, 18, 19 Actually, this should not be too surprising considering that farmers use antibiotics even when there is no disease because it helps animals put weight on. Why should you be any different?
- I understand that the scientific community keeps coming up with studies that "prove" that high fructose corn syrup does not excessively contribute to weight gain, but that's simply not true. Those studies achieve their results by restricting their focus to aspects that particularly favor the results they want to achieve. In fact, there are a number of other studies that have clearly demonstrated the relationship between HFCS and weight gain. The bottom line is that the different sugars are anything but identical. Sucrose, commonly known as table sugar, is comprised of two different sugars: glucose and fructose. Glucose and fructose are both simple sugars, naturally found in fruit, and both have the same number of calories; but research suggests there are important differences in how your body responds to them. 20 Glucose is absorbed directly into the bloodstream to produce energy. Fructose, which is used to sweeten soft drinks and many, many processed foods, on the other hand, is metabolized in the liver. The body reacts to glucose in the blood by producing insulin, which triggers feelings of fullness. Fructose doesn't stimulate insulin secretion, and if there's no insulin, you don't get the message that you're full and should stop eating. Consuming fructose also triggers more activity in areas of the brain involved in reward processing, which intensifies cravings for high-calorie foods such as candy, cookies, and pizza. The increased use of HFCS has significantly increased all of the problems associated with excess sugar consumption.
For decades I've been saying that weight management is about calories in VS calories out. However, I have also said that a number of factors can change how those two conditions play out. For example, as I pointed out earlier, muscle burns calories even when not being exercised; fat does not. That means that two people, given the same food intake and same level of exercise, will burn calories at a different rate depending on how much muscle VS fat their bodies contain. It's still calories in VS calories out. But if you've done the work to build the muscle, you're rewarded with more calories burned down the road with no extra effort required. The bottom line is that the more obese you get, the harder it is to burn calories; and since the world as a whole is getting more and more obese, people in general are finding it harder and harder to burn off excess calories. This study changes nothing. It merely reinforces what we already know.
I also question the data in the study both in terms of calories consumed and calories burned--primarily because all of the data was derived from surveys, and people are not always the best at realizing what they eat and how much they exercise. As I've pointed out before, studies have shown that people are now consuming 523 more calories a day than they were in 1970. We're talking about a pound of extra weight a week--52 pounds a year--that now has to be burned off. Is it any wonder that people are growing heavier? Compare that to the 6-10 pounds or extra weight that may have resulted from outside factors during the entire course of the study. Quite simply, any effect caused by outside factors is dwarfed by the difference in excess calories now consumed.
As for exercise, I have trouble with those numbers as presented in the study as well. The numbers don't add up. When you consider that adults sleep, on average 6 hours a day, work 8+ hours a day, and spend 12 hours and 4 minutes each day viewing major media on their TV, computer, phone, radio, and print, it doesn't leave any time for exercise.21 I mean none! According to the American Heart Association, people are less active due to technology and better mass transportation.22 In addition, they point out that sedentary jobs have increased 83% since 1950; physically active jobs now make up less than 20% of our workforce. As a reference point, in 1960, about half of the US workforce was physically active. And finally, our average workweek is longer. Full-time workers in the US now work about 47 hours a week--that's more than 350 extra hours worked each year.
In any case, even if the data that says people are exercising more is true, we're only talking about a couple of BMI points, on average, due to these outside factors. When people are 30, 40, 50 lbs. or more overweight, these factors would represent only a piece of the puzzle, and a very small piece at that. Ultimately, little has changed. It still comes down to:
- People are eating more than ever before.
- They are expending fewer calories than ever before.
If you want to lose weight, you absolutely have to:
- Cut the number of calories you're consuming.
- Find a way to increase the calories you're burning both through exercise and finding ways to expend more calories at work such as biking to work and using the stairs instead of the elevator.
And it wouldn't hurt to:
- Go organic to eliminate endocrine disruptors and antibiotics in your food.
- Get more sleep, even if that includes taking a power nap every day to catch up on shortened sleep at night.
- Set the thermostat to use less air conditioning in the summer and heating in the winter so that you force your body to increase brown fat levels to accommodate the larger temperature swings.
- Take time to smell the roses, metaphorically speaking. For any of a number of reasons, all related to your health, you need to drop stress levels so that you don't have elevated cortisol levels pushing your weight northwards. By the way, exercise will help with that too.23, 24 And if push comes to shove, there are both herbal and nutraceutical solutions as well.
- 1. A. Maralit. "Weight Loss was Easier in the '80s." Food World News. Oct 08, 2015. (Accessed 26 Oct 2015.) http://www.foodworldnews.com/articles/42689/20151008/weight-loss-80s-health-baby-boomers-millennials-generation-x-generation-y-obesity-canadian-institute-of-health-research-obesity-research-and-clinical-practice.htm
- 2. Olga Khazan. "Why It Was Easier to Be Skinny in the 1980s." The Atlantic. Sep 30, 2015. (Accessed 26 Oct 2015.) http://www.theatlantic.com/health/archive/2015/09/why-it-was-easier-to-be-skinny-in-the-1980s/407974
- 3. Susan Rinkunas. "It's harder to be thin than it was in the '80s." AOL. Oct 1, 2015. (Accessed 26 Oct 2015.) http://www.aol.com/article/2015/10/01/it-s-harder-to-be-thin-than-it-was-in-the-80s/21243862/
- 4. Carina Storrs. "Not mom's weight loss: For millennials, more than diet and exercise at play." CNN. October 2, 2015. (Accessed 26 Oct 2015.) http://www.cnn.com/2015/10/02/health/millennials-diet-exercise/
- 5. Brown RE, Sharma AM, Ardern CI, Mirdamadi P, Kuk JL. "Secular differences in the association between caloric intake, macronutrient intake, and physical activity with obesity." Obes Res Clin Pract. 2015 Sep 14. pii: S1871-403X(15)00121-0. http://www.ncbi.nlm.nih.gov/pubmed/26383959
- 6. Allison DB, Mentore JL, Heo M, et al. "Antipsychotic-induced weight gain: a comprehensive research synthesis." Am J Psychiatry. 1999 Nov;156(11):1686-96. http://www.ncbi.nlm.nih.gov/pubmed/10553730
- 7. Symonds ME, Pearce S, Bispham J, et al. "Timing of nutrient restriction and programming of fetal adipose tissue development." Proc Nutr Soc. 2004 Aug; 63(3):397-403. http://www.ncbi.nlm.nih.gov/pubmed/15373949/
- 8. Hansen JB, Kristiansen K. "Regulatory circuits controlling white versus brown adipocyte differentiation." Biochem J. 2006 Sep 1; 398(2):153-68. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1550312/
- 9. Ricquier D. Proc Nutr Soc. 2005 Feb; 64(1):47-52. "Respiration uncoupling and metabolism in the control of energy expenditure." http://www.ncbi.nlm.nih.gov/pubmed/15877922/
- 10. Wilkinson PW, Parkin JM, Pearlson J, et al. "Obesity in childhood: A community study in Newcastle upon Tyne." Lancet. 1977 Feb 12; 1(8007):350-2. http://www.ncbi.nlm.nih.gov/pubmed/64869/
- 11. Duran-Tauleria E, Rona RJ, Chinn S. "Factors associated with weight for height and skinfold thickness in British children." J Epidemiol Community Health. 1995 Oct; 49(5):466-73. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1060149/
- 12. Blair NJ, Thompson JM, Black PN, et al. "Risk factors for obesity in 7-year-old European children: the Auckland Birthweight Collaborative Study." Arch Dis Child. 2007 Oct; 92(10):866-71. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2083229/
- 13. Patrick Seale, Bryan Bjork, Wenli Yang, Shingo Kajimura1, Sherry Chin1, Bruce M. Spiegelman, et al. "PRDM16 controls a brown fat/skeletal muscle switch." Nature 454, 961-967 (21 August 2008). http://www.nature.com/nature/journal/v454/n7207/full/nature07182.html
- 14. Jeffrey M. Jones. "In U.S., 40% Get Less Than Recommended Amount of Sleep." Gallup. December 19, 2013. (Accessed 1 Nov 2015.) http://www.gallup.com/poll/166553/less-recommended-amount-sleep.aspx
- 15. Bjorvatn B, Sagen IM, et al. "The association between sleep duration, body mass index and metabolic measures in the Hordaland Health Study." J Sleep Res. 2007 Mar; 16(1):66-76. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2869.2007.00569.x/full
- 16. Knutson KL, Spiegel K, Penev P, Van Cauter E. "The metabolic consequences of sleep deprivation." Sleep Med Rev. 2007 Jun; 11(3):163-78. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1991337/
- 17. de Sá Del Fiol F, Tardelli Ferreira AC, et al. "Obesity and the use of antibiotics and probiotics in rats." Chemotherapy. 2014;60(3):162-7. http://www.karger.com/Article/FullText/371737
- 18. Schwartz BS, Pollak J, et al. "Antibiotic use and childhood body mass index trajectory." Int J Obes (Lond). 2015 Oct 21. http://www.ncbi.nlm.nih.gov/pubmed/26486756
- 19. Gérard P. "Gut microbiota and obesity." Cell Mol Life Sci. 2015 Oct 12. http://www.ncbi.nlm.nih.gov/pubmed/26459447
- 20. Page KA, Chan O, Arora J, et al. "Effects of Fructose vs Glucose on Regional Cerebral Blood Flow in Brain Regions Involved With Appetite and Reward Pathways." JAMA. 2013;309(1):63-70. http://jama.jamanetwork.com/article.aspx?articleID=1555133
- 21. "US Adults Spend 5.5 Hours with Video Content Each Day." eMarketer. 16 April 2015. (Accessed 1 Nov 2015.) http://www.emarketer.com/Article/US-Adults-Spend-55-Hours-with-Video-Content-Each-Day/1012362
- 22. "The Price of Inactivity." American Heat Association. Oct 26, 2015. (Accessed 1 Nov 2015.) http://www.heart.org/HEARTORG/GettingHealthy/PhysicalActivity/FitnessBasics/The-Price-of-Inactivity_UCM_307974_Article.jsp
- 23. "Physical Activity Reduces Stress." ADAA (Accessed 2 Nov 2015.) http://www.adaa.org/understanding-anxiety/related-illnesses/other-related-conditions/stress/physical-activity-reduces-st
- 24. "Exercise for Stress and Anxiety." ADAA (2 Nov 2015.) http://www.adaa.org/living-with-anxiety/managing-anxiety/exercise-stress-and-anxiety