Monthly Archives: March 2013

Obesity is not permanent

Take a group of obese people (> 250 lbs) and put them on a massive calorie restricted diet.  They lose weight and metabolic rate plummets.  Weight loss fail?  In most cases, yes.  But a recent study showed that the decrepit post-weight loss metabolic rate gradually improves in parallel with an increase in dietary fat ingestion to such a degree that even after two long years: totally food intake was almost back to normal, energy expenditure improved, and all this happened despite continual weight loss.  In other words, obesity is not permanent. 

creme brulee

Decreased energy density and changes in food selection following Roux-en-Y gastric bypass (Laurenius et al., 2013)

Statistically speaking, no diet on Earth comes close to RYGB in terms of weight loss success.  Long term.  Seemingly permanent.  It’s the closest thing to a cure we’ve got.

Laurenius

Body weight is down by 30%, and energy expenditure is rising faster than a speeding bullet.  because food intake is increasing while body weight is dropping – they’re probably more active too ** weight loss than more exercise –

But there’s a more mystical aspect to RYGB that warrants attention.  (it could be the increasing fat intake, but for now let’s just say it’s RYGB per se).  According to this pearl, weight loss of only 10% via diet alone causes energy expenditure crash by 394-500 kcal/d, and physiological replacement of leptin via subcutaneous injection can increase this by 234-454 kcal/d (Rosenbaum, Murphy, Heymsfield, Matthews, and Leibel, 2002).

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The curiosities of nicotin..ic acid

Niacin vs. ketosis

Part I.  Rodents

It is thought: niacin causes red itchy face (> 100 mg/d) and acutely lowers FFAs; chronically, it raises some questionable fraction of HDL (> 1000 mg/d) and probably causes diabetes.

It is speculated: niacin binds a particular “ketone” receptor (GPR109?) (physiological relevance?).

It is known: niacin is ketogenic in rats.  Repeat: niacin is ketogenic in rats.

Niacin aka nicotinic acid and nicotamide aka niacinamide both fulfill the requirement for Vitamin B3 (ie, prevent pellagra).  But only the former causes flushing… and only the former is ketogenic (two apparently unrelated phenomena).

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How to define a “healthy” diet. Period.

Whether you’re strictly adhering to a diet or just doing your own thing, if year after year your GP is prescribing more and more medications to stave off morbidity and keep you intact, then the diet you’re following is most likely Fail.  The same is true if your body weight is creeping upward or your quality of life is creeping downward.lunchables

The glaring Fail of all 3 diets in the recent Mediterranean Diet Study for the medications criteria threw up a huge red flag.  As a brief refresher, at baseline and 5 years later, prescription medication usage was as follows:

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Can MCTs skirt the need for strict keto?

Part I.  Ketones are made from fat in the liver.  But dietary fat has a lot of places to go and people to see, so it rarely gets to the liver en masse to a degree great enough to stimulate ketosis.  Not so much for medium chain triglycerides (MCTs).  Upon entry (ingestion), MCTs go to the liver and are metabolized to ketones without passing GO or collecting $200… but is this sufficient to reap the benefits of a ketogenic diet?

GourmetBacon

MCTs (C8-10) comprise ~14 of the fat in coconut oil, and 9.2% in dairy.  As such, average MCT intake is low – ~2% of total fat intake [because we eat a lot of vegetable oil and not a lot of coconuts].

Exhibit A.  Weight-loss diet that includes consumption of medium-chain triacylglycerol oil leads to a greater rate of weight and fat mass loss than does olive oil (St-Onge and Bosarge, 2008)

Healthy people assigned to either ~21grams of either MCTs or olive oil (~12% of total calories on a hypocaloric 1650 kcal/d weight loss diet) for 16 weeks:

This.St Onge BW

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