Tag Archives: empty calories

Paleo Plants and Carnivory

From what I gather, it’s been difficult to pinpoint the role of plants in the diet of our ancestors for a variety of reasons.  For example, evidence of plants on cooking tools and dental remains is suggestive but doesn’t disprove the possibility that said evidence came from preparing the plants for some other purpose (eg, tools, weapons, or medicine), or that the stomach contents of an herbivore was ingested (which gets partial credit).

That said, after reviewing a few studies on the topic (see below), it’s safe to say that plants were eaten, probably frequently, and the types & quantities varied seasonally & geographically.  Collectively, the data suggest we aren’t carnivores.

…you had to have something to hold you over until the next fish fell prey to your deadly hunting spear…

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Lipid Hypothesis 2.0: Eat Butter

The original lipid hypothesis stated, more or less, that lowering blood cholesterol would reduce premature mortality from heart disease.  At the time, it was thought that dietary cholesterol and saturated fat increased the ‘bad’ type of blood cholesterol, so the advice was to restrict those foods.  All of that was wrong.

Time

Lipid Hypothesis 2.0: Eat Butter

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Circadian disruptions impact behavior and metabolism in a tissue-specific manner.

The control of circadian gene expression is complex, with layer upon layer of suppressors and enhancers, numerous transcription factors, and a lot of interactions.  A gross oversimplification: Clock and Bmal1 are positive regulators of circadian gene expression; Per and Cry are negative (you don’t really need to know any of this).

 

Some pretty cool progress has been made in examining the effects of global and tissue-specific deletion of circadian rhythm-related transcription factors.  Bear with me 🙂

For example, global Bmal1 knockout mice (ie, mice that don’t express Bmal1 anywhere in their whole body.  Zero Bmal1.  Nil.) (Lamia et al., 2008).  These mice are obese, and exhibit impaired glucose tolerance yet improved insulin sensitivity.

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Does junk food make you lazy?

From Times LIVE: “Does junk food make you lazy?” 

“A diet rich in processed foods and fat – and the extra weight that comes along with it – may actually cause fatigue, a lack of motivation and decreased performance, according to a recent study involving lab rats… excessive consumption of processed and fat-rich foods affects our motivation as well as our overall health.”

(this is categorically false as both diets used in the study being discussed were very low in fat.)

And from Psych Central: “Rat study shows junk food can make you lazy

The theory itself isn’t too far-fetched: a crap diet can cause weight gain and reduced energy expenditure, or a tendency to minimize any kind of physical activity… instead of: “’laziness’ causes obesity.”  And whether or not it’s true, unlike what some would have you believe, this wasn’t the study to prove it.

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Insulin, dietary fat, and calories: context matters!

Jane Plain recently wrote a great article about the relationship between insulin, dietary fat, and calories.  There are a lot of data on this topic, which collectively suggest: context matters! 

For example,

Insulin and ketone responses to ingestion of MCTs and LCTs in man. (Pi-Sunyer et al., 1969)

14 healthy subjects, overnight fasted; dose: 1g/kg.

In brief, MCTs are more insulinogenic than corn oil.  But it’s not a lot of insulin.  Really.  Enough to inhibit lipolysis, perhaps, but that’s not saying much… & certainly not enough to induce hypoglycemia.

Pi-Sunyer MCT Corn oil

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Protein Leverage Hypothesis

Inverse Carb Leverage HypothesisTM

Protein Leverage Hypothesis: Dude eats 15% protein on a 2000 kcal diet (75 g protein).  Exchange 25 grams of protein with carb, and he’s now eating 10% protein on a 2000 kcal diet (50 g protein).  Theory states Dude will increase total food intake to get back those 25 grams.

Ergo, Protein Leverage Hypothesis:

protein leverage hypothesis

Disclaimer: I don’t care much for the Protein Leverage Hypothesis.  It might be true, but that doesn’t mean it matters.  It works well in rodents, but obese patients eat tons of protein.  The rebuttal to this is that the protein in their diet is too diluted with other [empty] calories.  They’re overeating because of low protein %.

The flipside, confirmed ad nauseam in rodent studies, is that frank protein deficiency increases food intake.  Frank protein deficiency means negative nitrogen balance & tissue loss… not just skeletal muscle; organs, too.  Incompatible with survival.

Feed someone a low protein low fat diet, they get hungry.  If it’s ad libitum, they eat more.

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Nutrition Disinformation III

but they actually get it right this time.   Big HT to George Henderson for bringing this ms to my attention.

In Nutrition Disinformation, Part I, the Mediterranean diets employed by Estruch & colleagues were discussed.  The study subjects’ need for antidiabetic drugs, insulin, and anti-platelets all increased over the course of 5 years.  The media and even the authors themselves reported the opposite, touting the benefits of Mediterranean diets.  Thus begat the Nutrition Disinformation series.

Nutrition Disinformation 2.0 was a follow-up to an older post on the Look AHEAD study, when the results were finally published.  The intensive lifestyle intervention consisted of a pharmaceutical-grade low fat diet (ie, LFD + a little bit of Orlistat), and exercise.  By the end of 10 years, medication use was modestly lower in the intensive lifestyle group compared to controls, but it was markedly increased from baseline.  Therefore, I deemed it egregious to say their intervention was “healthy.”  In the context of Nutrition Disinformation, “healthy” means you’re getting better.  The need for insulin, statins, and anti-hypertensives should decline if you’re getting better.

In part 3 of the series, Yancy must’ve been following the Nutrition Disinformation series 🙂 and decided to conduct a subgroup analysis on the patients in his previous low carb vs. low fat + Orlistat study.  Weight loss was roughly similar, but all other biomarkers improved more on low carb.  In the new publication, Yancy analyzed data selectively from the diabetic patients in his original study to generate a “Medication Effect Score (MES).”  MES is based on what percentage of  the maximum dose was a patient given, and adjusted for the median decline in HbA1c experienced by patients on said drug.  A bit convoluted, but I’m on board (at least tentatively).

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Calories schmalories, alcohol, and chocolate

Some calories count, others don’t.  Some calories work in some people, but not others.  Does this sound like an irrefutable Law of Nature?  No, but it is a perfectly acceptable tenet of the Laws of Energy Balance (a construct of my design).

Do alcohol calories count?  Sometimes, but not this time:

The energy cost of the metabolism of drugs, including ethanol (Pirola & Lieber 1972)

This was a study on bona fide alcoholics who participated because they were promised treatment.  Metabolic ward.  FYI, one gram of alcohol burned in a calorimeter produces ~7.1 kilocalories; alcohol = 7.1 kcal/g.

Calories required to maintain body weight (ie, = total energy expenditure) was assessed the old-fashioned way: feeding them enough calories to maintain a stable body weight – they counted calories but relied on the bathroom scale to establish a baseline.  #TPMC.  After a week of weight stability, they ISOCALORICALLY exchanged carbohydrates for alcohol, and broke CICO.

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Silent Leptin Resistance

Conventional leptin resistance has something do with obesity.  It is known.  Silent leptin resistance is … err … complicated. 

Divide and conquer

Fructose-induced leptin resistance exacerbates weight gain in response to subsequent high-fat feeding (Shapiro, Scarpace, et al., 2008 AJP)

A remarkable 60% fructose diet fed to rats for 6 months had absolutely no effect on energy balance.  Nil. QED.
Fig 1

Food intake and body weight were unaffected because the levels of and sensitivity to endogenous leptin were identical in both groups.

Enter the Dragon

Enter the Dragon

“Silent Leptin Resistance” – The fructose-fed rats are, however, profoundly resistant to the satiating effects of Metreleptin (a pharmaceutical grade injectable leptin analog):

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On calorie information posted in restaurants

“This is biology, not mathematics.”

It’s law in some places.  It’s a burden on restaurants.  And it will do nothing for the cause – like trying to put out a candle by pressing the off button on your remote control.  In other words, a waste.

Here’s some of the “science” behind it.

Exhibit A.
In a study by Dumanovsky, fast-food customers were surveyed prior to and after mandatory calorie labeling in New York.  25% of the people reported “seeing calorie information,” and 10% of them said it affected their buying decision (ie, 2.5% of all fast-food consumers surveyed thought they knew enough about “calories” to be scared of them).  After the law went into effect, 64% of people noticed the calorie information, and 20% of them were affected by it (=12.8% of all fast-food consumers thought they knew enough about “calories” to be scared of them).  Sooo, the proportion of people making misinformed decisions quintupled.  Calorie Labeling = Nutrition Disinformation.  It’s misleading, and usually wrong.

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