Tag Archives: diet

The faux-low carb mouse and a diatribe

The faux-low carb mouse

Hyperinsulinemia drives diet-induced obesity blah blah blah (Mehran et al., 2012)

The researchers generated a mouse with half as much insulin as normal mice.  Physiological insulin levels remain intact, but hyperinsulinemia is genetically inhibited.  For the sake of simplicity, we’ll call them “InsKO.”

When fed a high fat diet, normal mice become markedly hyperinsulinemic (pink line) whereas InsKO mice maintain relatively normal insulin levels (red line).  Blue lines are chow-fed mice; similar trend but less interesting.

divide and conquer

InsKO mice don’t get fat,

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Sir Philip Randle and the effects of blocking fat oxidation

The Randle Cycle, put forth in 1963, dictates that increased fatty acid oxidation inhibits glucose uptake and increased glucose oxidation inhibits fatty acid oxidation – it just makes sense.  Insulin enhances glucose uptake and oxidation while suppressing lipolysis; growth hormone, cortisol, and adrenaline enhance lipolysis and fatty acid oxidation which suppresses glucose oxidation.  Low carbohydrate diets reduce insulin, and the reduced glucose oxidation is metabolically irrelevant because of reduced glucose intake (by definition).  This is critical information.  And as a student of basic intermediary metabolism, I prefer the Randle Cycle over any number of alphabet soup recipes to explain metabolic phenotypes (eg, fat and carbs as opposed to IRS, Akt, Jnk, ERK, etc., etc.).  Many valuable lessons can be learned from understanding permutations of the Randle Cycle.

For example,

Inhibition of carnitine palmitoyltransferase-1 activity alleviates insulin resistance in diet-induced obese mice (Keung et al., 2012)

divide and conquer

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NRT = nicotine replacement therapy

NRT improves quitting success rates and reduces cessation-induced weight gain.  It’s a fact; and there are a lot of anti-addictive pharmacological interventions that do too.

Dear obesity researchers, primary care physicians, and smokers,
Pay attention.
Sincerely,
Bill

Rimonabant is the anti-“munchies” drug that blocks the marijuana receptor CB1.  It causes weight loss.  But 20 mg daily also increases the odds of successfully quitting smoking by 50 – 60% (Cahill and Ussher, 2007).

Relevance?
Marijuana: not really addictive.
Obesity diets: delicious, but not really addictive.
Cigarettes: definitely addictive.
Rimonabant: anti-addictive.  It causes weight loss in overweight but not lean people, perhaps because lean people don’t eat obesity diets (?).

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The curious effects of calories in mice

What is the biological impact of a history of obesity and weight loss?  The metabolic trajectory of two calorically restricted skinny mice depends entirely upon whether or not they used to be fat.  The end of this story might be: ‘Tis better to have lost and re-gained than never to have lost at all; or it’s just an interesting new take on the body weight set point theory.

Caloric restriction chronically impairs metabolic programming in mice (Kirchner et al., 2012)

divide and conquer

Part 1.
Study 1. Calorie restricted lean mice: the effect of diet composition.

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Coffee and cigars, the breakfast of champions

Or more specifically, caffeine and nicotine… or really just nicotine.  Today is about the lesser of two evils: nicotine, Mother Nature’s little helper (the other evil being cigarettes [not coffee]).  This curious little molecule is an anti-inflammatory memory boosting appetite suppressant.  If it didn’t screw with the reward mechanisms in your brain, it’d be a vitamin. Part 1.  Cigarettes, nicotine, and metabolic function Exhibit A: Activation of the cholinergic anti-inflammatory pathway ameliorates obesity-induced inflammation and insulin resistance  (Wang et al., 2011) translation: “nicotine is good for mice.” Continue reading

Fish oil. Pills or directly from the source? Opus 118.

As a proponent of consuming fatty fish (sardines, salmon, etc.), I was interested to read the new fish oil study; as an opponent of meta-analyses, however, not so much.  A meta-analysis is a type of study whereby the researcher thinks of something they want to prove, then cherry picks studies that best support their point.  Or perhaps I’m just biased.  Nonetheless,

Association between fish consumption, long chain omega 3 fatty acids, and risk of cerebrovascular disease: systematic review and meta-analysis (Chowdhury et al., 2012)

In brief, regarding whole fish consumption, 3 servings per week reduced stroke risk by 6% and 5 servings by 12%.  Surprisingly, there was no effect of fish oil pills that contained ~1.8 grams of long chain omega 3 fatty acids.  What this study lacks is any information about the dose of EPA and DHA (the major bioactive fatty acids in fatty fish); and with 38 studies analyzed, I’m not about to try to figure it out (sorry team)…  a serving of fish can have anywhere from 0 to 1 gram of EPA and DHA; 1.8 grams of long chain omega 3 fatty acids can have anywhere from 0 to 1.8 grams of EPA and DHA.  Therefore, I’ll resort to reviewing two of my favorite fish studies of all time: DART and GISSI.  For a more detailed review of fish oils and these studies, check out The poor, misunderstood calorie (chapter 9).

divide and conquer

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“An adult conversation” about the Look AHEAD study

Extra! Extra!    Read all about it!  (after you sign up for the new EMAIL NOTIFICATIONS on the right)

Moderate weight loss alone doesn’t lower heart disease risk in diabetics, study shows
Diabetes study ends early with a surprising result
NIH trial of lifestyle intervention for type 2 diabetes stopped for futility after 11 years

Notice none of the headlines read “Low fat diet is not heart-healthy for diabetics,” but that’s exactly what the latest epic fail demonstrated.  Reminiscent of the Women’s Health Initiative (circa 2006), the Look Ahead study tested a long-term low fat diet in diabetics.  If a protective effect had been shown, this study would’ve gone done in the history books as definitive proof that a low fat diet is superior.  But it wasn’t, and unfortunately that probably won’t count as anything for the opposition.  In brief, the planned 14 year study was stopped after 11.5 years because cardiovascular events weren’t lowered by the low fat diet (and might even have been increased; the manuscript hasn’t been published [yet?]).

The Women’s Health Initiative, which cost taxpayers something in the ballpark of $625,000,000 (six hundred twenty five million dollars > a half billion), showed that reducing dietary fat by 8 percentage points (from 37.8% to 28.8%; a 23.8% reduction) for 8 years had no effect on heart health and was even detrimental for people with CVD at baseline.  I repeat: CVD patients assigned to the low fat dietary intervention experienced more cardiovascular events than those in the control group (you heard it here first).  But for some reason, the Look AHEAD researchers thought they might get a different result if they tried this in diabetics?  A low fat high carb diet in patients with bona fide carbohydrate intolerance?  really?

REALLY?

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[ketogenic] elite artistic gymnasts

Before you say anything, “elite artistic gymnasts” could probably beat you in a race running backwards.  (with you running forwards.)  They are elite athletes.  And given a sufficient keto-adaptation period, they perform better sans carbs.

Ketogenic diet does not affect strength performance in elite artistic gymnasts  (Paoli et al., 2012)

This study looked at body composition and various performance measures before and after 30 days of a very low carbohydrate ketogenic diet (“VLCKD,” < 25 grams of carbohydrate per day) or a normal diet (“WD,” > 250 grams of carbs per day).  25 grams of carbs is very very low, less than Atkins and Kwasniewski.  On the other hand, 41% protein is pretty high.

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The Laws of Energy Balance FTW!

Weight loss maintenance is not determined by calorie intake… or physical activity… but by The Laws of Energy Balance FTW!!!

Odd, the sensation I felt when reading this news release (gloating?).  As reported at a meeting of the Obesity Society, results from the Utah Obesity Study of gastric bypass patients 2 and 6 years after surgery.  By the 2 year mark, they lost over 100 pounds, or 36% of their starting weight (went from 296 to 189 pounds).  Energy expenditure declined from 2201 to 1736 kcal/day.  Food intake went from 2085 to 1638 kcal/day.  (Hint: it’s no coincidence that energy expenditure and food intake declined to the exact same degree.)  Physical activity and fitness levels increased.

By the 6 year mark, they still weighed 29% less than their starting weight.  N.B. that’s an amazing level of success, it’s virtually unheard of in diet intervention studies.  +1 for gastric bypass; -1 for nutrition.

Here’s what piqued my interest: during the gradual increase from 189 pounds to 210 pounds, which occurred between years 2 and 6 post-surgery, the most significant factor associated with weight regain was not calorie intake or physical activity… it was metabolic rate.  This represents another fail for “eat less move more,” and a win for the Laws of Energy Balance.

So what’s this got to do with The poor, misunderstood calorie?

what we know about metabolic rate:

1)      It’s invisible.

2)      Fructose vs. The Laws of Energy Balance (circa December, 2011): sugar-sweetened beverages can cause fat gain, not by providing excess calories, but by reducing metabolic rate.

3)      Holiday feasts, the freshman 15, and damage control (circa January 2012): overeating a high protein diet causes less fat gain than overeating anything else because it increases metabolic rate.

4)      Missing: 300 kilocalories (circa July 2012):  after losing weight, subjects assigned to the low carb diet maintained a higher metabolic rate than those on an isocaloric low fat diet.

“Eat less move more” is not the answer.  But eating less sugar, more protein, and fewer carbs might be.  Nutrition matters.

calories proper

Protein bar takedown, part III (or V)

No more pretense or cute backstory; I just like reviewing ingredient profiles of protein bars.  It’s a hobby of mine:
Candy in disguise, Op. 73 (circa April 2012)
Decepticon Promicor (soluble corn fiber), Op. 81 (June 2012)
Candy in disguise II, Op. 87 (July 2012)
Protein bar round-up, take II (September 2012)

See?

This is a review of Netrition’s “highest rated” bars.  Important notes about this category: these are not necessarily “new” protein bars, or even the bars everyone buy (“best sellers”).  They are the bars everyone who votes like the most.  They’re not the healthiest either… but some come close.   Continue reading