{"id":1108,"date":"2016-08-17T15:17:31","date_gmt":"2016-08-17T15:17:31","guid":{"rendered":"http:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/?p=1108"},"modified":"2017-08-21T10:49:55","modified_gmt":"2017-08-21T10:49:55","slug":"primary-care-corner-with-geoffrey-modest-md-weight-loss-and-resting-metabolic-rate","status":"publish","type":"post","link":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2016\/08\/17\/primary-care-corner-with-geoffrey-modest-md-weight-loss-and-resting-metabolic-rate\/","title":{"rendered":"Primary Care Corner with Geoffrey Modest MD: Weight Loss and Resting Metabolic Rate"},"content":{"rendered":"<p><strong>By Dr. Geoffrey Modest<\/strong><\/p>\n<p>One of the hardest tasks for us and our patients is maintaining weight loss in those who are\u00a0overweight and obese. A recent NIH study looked at this issue, finding that people who had lost a lot of weight had long-term\u00a0&#8220;metabolic adaptation&#8221; leading to a significant <strong>lowering <\/strong>of resting metabolic rate (RMR) and much less overall energy expenditure\u00a0(see\u00a0doi:10.1002\/oby.21538 ). This study looked at 14 of\u00a0the\u00a016 &#8220;Biggest Loser&#8221; competitors from this\u00a0televised weight-loss competition.<\/p>\n<p>Details:<\/p>\n<ul>\n<li>Baseline: median\u00a0age 35, 6 men\/8 women,\u00a0weight 149 kg, BMI 49.5<\/li>\n<li>At the end of the competition (30 weeks), through an aggressive program of diet and exercise,\u00a0the mean weight loss was 58.3 kg, BMI\u00a0deceased\u00a0to 30,\u00a0and the RMR decreased 610 kcal\/day below baseline (this decrease in RMR was expected, as per a multitude of prior studies).<\/li>\n<li>The following hormone levels improved dramatically after weight loss (at 30 weeks): insulin, C-peptide, triglycerides, HDL, adiponectin, T3, leptin, and the calculated HOMA-IR (which correlates with\u00a0insulin resistance)<\/li>\n<li>This weight loss was primarily from fat mass but with\u00a0relative preservation of fat-free mass [likely from the intensive exercise training]<\/li>\n<li>After 6 years:\n<ul>\n<li>Participants\u00a0regained a mean of\u00a041.0 kg (though wide variation: 1 person did not regain weight, though\u00a05 were\u00a0within\u00a01% of their baseline weight or above),\u00a080% of the weight gain was from fat However, 6 years later\u00a0the RMR remained 704 kcal\/d below baseline (actually non-significantly\u00a0<strong>worse <\/strong>than\u00a0the RMR after the remarkable initial\u00a0weight loss), and metabolic adaptation was down\u00a0499 kcal\/d [I believe this is basically RMR corrected for fat-free mass, but this was never clearly stated in the study]<\/li>\n<\/ul>\n<\/li>\n<li>The metabolic adaptation at the end of the competition (30 weeks) correlated\u00a0with\u00a0the amount of weight loss, did\u00a0not correlate\u00a0with the ultimate weight regained, but it\u00a0did improve\u00a0some in those who regained the most weight (and<strong> metabolic adaptation<\/strong><strong>did not improve at all in those who maintained the weight loss<\/strong>, with a dose-response curve)<\/li>\n<\/ul>\n<p>Commentary:<\/p>\n<ul>\n<li>Background:\u00a0from the initial studies, the physiologic phenomenon of\u00a0metabolic adaptation (also called &#8220;adaptive thermogenesis&#8221;, or AT) reflects\u00a0the evolutionary imperative\u00a0that the body readjusts to maximize efficiency in times of starvation by lowering energy expenditure.\u00a0AT has been\u00a0found to be independent of changes in fat-free mass and takes weeks to develop;\u00a0in earlier studies it seemed to be independent of the magnitude of weight loss after\u00a0reaching the\u00a0peak of\u00a0a 10% weight loss threshold\u00a0(see\u00a0Muller MJ. Obesity 2013; 21: 218). Adaptive thermogenesis\u00a0is associated with a variety of changes related to decreases in resting and total energy expenditure, including decreased sympathetic nervous system activity, T3, and\u00a0leptin. There are some early suggestions from animal studies that giving exogenous\u00a0leptin restores at least some of the decreased\u00a0RMR<\/li>\n<li>Many studies have shown that\u00a0in the setting of starvation, the body in fact lowers its metabolism to conserve energy and weight. One perhaps interesting issue is the role of genetics (I\u00a0have seen nothing\u00a0to answer these questions\u00a0in searching around\u00a0on this). For example, is there a difference in the metabolic adaptation\/changes in RMR in those who are overweight but\u00a0coming from families with lots of obesity vs those where there is not an apparent genetic burden for obesity?\u00a0Overall, obese individuals are more likely to have lower RMR from several studies, but are\u00a0those who are lean at baseline but have a\u00a0lower RMR\u00a0more likely to develop obesity than those with a higher RMR? Not so clear. At least some studies suggest that eating leads to thermogenesis (i.e., it might be that even in those with low metabolic rates, eating increases\u00a0their metabolic\u00a0rates enough that they do not become obese; and, therefore, perhaps there is no causal effect of low metabolic rate and eventual obesity). In fact some small studies noting lower RMR in obese women found that\u00a0the RMR was actually higher in obese women if one corrected for fat-free body mass (see Hoffmans M. Int J Obesity 1979;3(2):111). A bit of a bag of worms&#8230;.<\/li>\n<li>Interestingly, bariatric surgery does not create the same issue of metabolic adaptation as does starvation: with surgery\u00a0there seems to be an effective reset of the body&#8217;s weight set-point within a year of bariatric surgery, for unknown reasons (see Hao Z. Obesity (Silver Spring) 2016; 24:\u00a0654)<\/li>\n<li>There were a couple of interesting studies (both\u00a0from the same group) suggesting that weight loss by a low glycemic diet causes less decrease in RMR:\n<ul>\n<li>One found\u00a0thatresting energy expenditure in overweight\/obese young adults decreased much less with a low glycemic index diet (96 kcal\/d, or 5.9%)\u00a0vs a low\u00a0fat\u00a0diet (176 kcal\/d, or 10.6%) [Those on low GI\u00a0diet\u00a0also had less hunger, improved\u00a0insulin\u00a0resistance,\u00a0triglycerides, CRP and blood pressure].\u00a0See\u00a0Pereira MA. JAMA 2004; 292: 2482<\/li>\n<li>This was\u00a0confirmed in another study\u00a0(see\u00a0EbbelingJAMA 2012; 307: 2627), finding that\u00a0isocaloric\u00a0feeding led to decreases in\u00a0resting energy expenditure of 205 kcal\/d in a low fat diet, 166 kcal\/d in a low-glycemic\u00a0index\u00a0diet\u00a0and 138 kcal\/d in a very low-carbohydrate diet. Total energy expenditure decreased 423, 297 and 97 kcal\/d respectively.<\/li>\n<\/ul>\n<\/li>\n<li>But, the bottom line from this study: at least in the case of those with severe morbid obesity (median\u00a0BMI of 50), losing weight had the anticipated decrease in energy expenditure, but <strong>even 6 years later, this lowering of RMR\u00a0through metabolic adaptation\u00a0did not revert to their baseline<\/strong>. What does that mean? For one thing, it reinforces what many patients and clinicians know: losing weight is really hard to do, and if weight is lost, it is really really hard to keep it off in the long-term. Which doesn&#8217;t mean that we all should give up. Just that this understanding is really important, and we all (including patients) should really try to avoid the blame-game (some variant of &#8220;if you really want to lose\u00a0weight, you can&#8221; morphing\u00a0to &#8220;if you don&#8217;t lose weight, it reflects your lack of will-power, tenacity, ability to get things accomplished&#8230;.&#8221;). and, my suggestion is that, given the remarkable difficulty in losing weight, those so motivated need lots of hand-holding:\u00a0seeing them frequently to discuss how they are doing\u00a0and\u00a0collectively deciding on\u00a0adjustments, encouraging lots of exercise to help maintain the weight loss, and overall\u00a0collectively setting often small goals and slowly ramping them up as the patient is capable of doing (understanding that there will be bumps along the way). My guess is that this approach\u00a0works much better than: &#8220;great, you understand what you need to do to lose weight, come back in 3-6 months&#8221;.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Primary Care Corner with Geoffrey Modest MD: Weight Loss and Resting Metabolic Rate [&#8230;]<\/p>\n<p><a class=\"btn btn-secondary understrap-read-more-link\" href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2016\/08\/17\/primary-care-corner-with-geoffrey-modest-md-weight-loss-and-resting-metabolic-rate\/\">Read More&#8230;<\/a><\/p>\n","protected":false},"author":148,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[14283],"tags":[],"class_list":["post-1108","post","type-post","status-publish","format-standard","hentry","category-archive"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/1108","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/users\/148"}],"replies":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/comments?post=1108"}],"version-history":[{"count":0,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/1108\/revisions"}],"wp:attachment":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/media?parent=1108"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/categories?post=1108"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/tags?post=1108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}