{"id":6209,"date":"2015-03-12T01:46:38","date_gmt":"2015-03-12T00:46:38","guid":{"rendered":"https:\/\/blogs.bmj.com\/bjsm\/?p=6209"},"modified":"2015-03-18T09:23:00","modified_gmt":"2015-03-18T08:23:00","slug":"part-1-to-lchf-or-not-to-lchf-thats-the-dietary-question","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/bjsm\/2015\/03\/12\/part-1-to-lchf-or-not-to-lchf-thats-the-dietary-question\/","title":{"rendered":"PART 1: To #LCHF or not to #LCHF – that\u2019s the dietary question! \u00a0"},"content":{"rendered":"

By @JohannWindt<\/a><\/span>, @Liam_West<\/a><\/span> &\u00a0@AniaTarazi<\/span><\/a><\/p>\n

\"Cape<\/a>
Cape Town International Convention Centre<\/figcaption><\/figure>\n

Attendees of the 2015 Old Mutual Health Convention were fattened with four full days of low-carb, high fat (#LCHF) information #PunIntended. For brief summaries, see daily blogs of Day 1<\/a><\/span>, Day 2<\/a><\/span>, and Day 3<\/a><\/span>. Combining our notes, conference speaker interviews, and your questions, #TeamBJSM hope this blog captures and summarizes the main scientific research presented at the summit. We have hyperlinked relevant papers in green for you to make up your own mind about the diet – #NoBias. There will be\u00a0two parts: “#LCHF and #Health” and the second, “#LCHF and Performance”. Here, in part 1, we look at LCHF in respect to\u00a0weight loss, cardiovascular risk and glycemic control and answered the common misconceptions about the diet.<\/p>\n

#LCHF AND #HEALTH<\/strong><\/span><\/p>\n

#LCHF for weight loss:<\/strong><\/span><\/p>\n

Physiological Basis – Hormonal Model Adopted<\/em><\/strong><\/span> – The central basis of the low-carbohydrate diet is adoption of the hormonal model of obesity, as opposed to a strictly energy balance model. They suggest that a purely calorie-based model (energy in vs. energy out) is insufficient, and the interplay of dietary intake, hormonal and physiological responses is key to understanding weight control. Most speakers highlighted the role of dietary carbohydrates in raising insulin levels, thereby encouraging the body to store fat (de novo lipogenesis), and block fat breakdown (lipolysis). Support for this model includes differential weight loss in isocaloric conditions<\/a><\/span>, and different weight loss in low-carbohydrate vs. low fat diets, dependent upon insulin resistance. Bonus reading here<\/a> <\/span>& here<\/a><\/span>.<\/p>\n

Trial Evidence – Low Carbohydrate Diets vs. Other Diets<\/em><\/strong><\/span> \u2013 A number of speakers presented evidence that low carb diets have outperformed low-fat diets (related reading; one<\/a><\/span>, two<\/a><\/span>, three<\/a><\/span>) \u00a0and low glycemic index diets<\/a><\/span>\u00a0 in randomized trials of weight loss. This observation has been picked up in a number of systematic reviews regarding the efficacy of low carbohydrate diets \u2013 links to read here; one<\/a><\/span>, two<\/a><\/span> & three<\/a><\/span>. Notably, it was identified the low-fat diets were deliberately energy controlled (with prescribed kcal to induce weight loss), while the low-carbohydrate diets were unrestricted in energy intake, yet still outperformed low-fat counterparts.<\/p>\n

Caveats and Misconceptions<\/em><\/strong><\/span> \u2013 First a calorie is a calorie. It\u2019s a unit of energy, it measures the potential energy food can release. Therefore #CaloriesStillCount. But, it must be emphasised, two equal calories can produce different biological effects to body fat or body weight, i.e. a calorie of protein vs a calorie of refined carb. Second, carb intake leading to fat storage is an oversimplification. Dr. Jason Fung aptly presented that the \u201ccarbs leading to insulin leading to fat\u201d hormonal model is a part of the puzzle, but fails to take into account all aspects. With the cycle of increased serum insulin, leading to insulin resistance, causing higher serum insulin, etc. at the center of the model, he identified three central players that all link to Insulin<\/strong>:<\/p>\n