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Professor Ludwig vs. Stephan Guyenet on Insulin vs. Calories

Is our weight mostly controlled by hormones or by the brain? Is it about normalizing our fat-storing hormones (mainly insulin) or is it just about deciding not to overeat?

The second answer has been the most commonly believed one, and it’s been a giant failure. We need new ideas that actually work. So we need to find the truth.

The old arguments in this interminable debate are nicely packaged by the formerly popular blogger Stephan Guyenet, PhD, at Whole Health Source: Always Hungry? It’s Probably Not Your Insulin

As a reply Professor David Ludwig just published this: Ludwig Responds to Whole Health Source Article

Who wins?

So who wins? The way I see it they are both wrong, but Professor Ludwig is much less wrong. 

Insulin levels and future weight gain

The argument from Guyenet that “High insulin levels do not predict future weight gain” and calling it “a basic prediction of the hypothesis” is simply based on a misunderstanding. Of course it does not. High insulin levels just predict (very accurately) already being obese.

I don’t think Ludwig answers this quite right. This argument from Guyenet is silly and needs no high science to answer.

If high insulin levels predicted future weight gain then obese people (who almost always have high insulin) would blow up like balloons. They would never stop gaining. In fact they would gain weight faster and faster until they exploded á la Monty Python.

Conversely, if low insulin levels predicted weight loss then thin people (who almost always have low insulin) would continue losing weight forever, until they disappeared.

Of course, neither of these ludicrous predictions are ever going to happen. Instead the body quickly reaches an equilibrium, where a certain average insulin level corresponds to a given fatness level. This is why obese people often maintain about the same body fatness over years or decades.

So: High insulin does not predict future weight gain, it predicts already being obese.

Weight Control – A Question of Calories or Insulin? – Dr. Andreas Eenfeldt4.6 out of 5 stars5 star73%4 star16%3 star6%2 star0%1 star3%83 ratings8336:26This correction also invalidates Guyenet’s following argument, about a there not being a “positive feedback” when losing weight. Again, of course not.

I discuss these misconceptions in more detail in a 2015 presentation (click image to the right).

Where Ludwig may be wrong

I think Professor Ludwig (as well as Taubes in GCBC) over-simplify the idea of “internal starvation” as a driver of weight gain. As Guyenet rightly points out, blood levels of fat and glucose on average tend to be higher in people with obesity.

Professor Ludwig does not have a fully satisfactory answer here, even if he correctly points out that episodes of low blood sugar is common some time after consuming high GI carbohydrates.

Probably a more correct way to look at this is to not only consider absolute levels of fat and glucose, but also changes in these nutrients. I.e. rapidly falling levels of nutrients in the blood may trigger hunger. Even if they are only falling lower than what is normal in the obese individual, not necessarily lower than what is normal in thin people. The body only knows itself.

Bottom Line: What works?

While it’s highly exciting to watch scientists disagree and quote studies, there is something more important: What actually works? How do you eat to lose weight?

People have been losing weight for hundreds of years using low carb. Conversely people have been gaining unprecedented amounts of weight for decades, just trying to eat less.

At least 20 high-quality weight loss studies back this up: low carb simply works better. More weight loss – with no need for hunger or calorie restriction.

It just works.

Try it for free

Low Carb for Beginners

Take the 2-Week Low-Carb Challenge

Do you want MORE science stuff?

How to Lose Weight – the “Magic” vs. the Insulin Way

Always Hungry? Here’s the Book for You

Low Carb Made Easy How to Lose Weight Low-Carb Recipes Low-Carb Success Stories

8 Comments

  1. George Henderson (@puddleg)
    In my understanding, "internal starvation" can also be a matter of substrate cycling. For example, in diabetes glucose is taken up by the liver, independent of insulin, due to its elevated concentration, undergoes glycolysis, is converted to acetyl-CoA and oxaloacetate, then merely used to make more glucose, because glucagon dominates. Fatty acids are similarly cycled to other fatty acids. These cycles waste most of the energy they produce. So starvation is relative. Diabetes is an extreme example, but it''s likely that similar things happen whenever the metabolic hormones, especially insulin and glucagon, are over-supplied and out of balance, and whenever substrate is excessive, as it will be during weight gain or steady-state obesity.
  2. Mathieu
    When I read GCBC I remember having a very different understanding of "internal starvation". My impression was that this starvation was at the cellular (non-adipocite) level and caused by a defect in fuel partitioning, which ends up manifesting itself as psychological hunger.

    I remember him citing examples of mice studies where the hormonally "broken" mice would even waste organ tissue to the point where they died of starvation with a significant amount of remaining body fat. The idea is that fuel partitioning can be altered with low-carb in a way that there is less of this cellular starvation which would manifest itself as lower psychological hunger, and would be one reason why hunger auto-regulates on low-carb.

    This might be totally false, and if its true the actual mechanisms are definitely not worked out, but that is what I took Taubes to mean. Was my impression way off?

  3. Nate
    Well, as T1D, I can say that i have experienced Dr. Eenfeldt's theory that hunger could be dependent on the speed of blood sugar lowering. While I was eating a high carb diet, a mistake in balancing my food intake and insulin doses could cause a rapid lowering of blood glucose and thus intense hunger. Trying to only eat a small amount of glucose to bring me back to a normal blood sugar level took a lot of discipline, which most often rapidly decreased also. LCHF has reduced that intense hunger a lot. Hunger is truly a relative thing.
    Reply: #6
  4. Mike
    I like how Andreas refers to Guyenet as "the formerly popular blogger".
  5. Ian
    Most of the stuff in GCBC comes from Gary Taubes's interviews and exhaustive (he jokes "exhausting") research pertaining to work done over 50 years ago. It seems to me insulin must be a major culprit in metabolic syndrome, possibly synonymous with it, and failure to burn ketones will probably prove to be the key. But Taubes hasn't stopped there. His non-industry funded organization, NuSi, is putting their money where their mouth is, and testing these claims.
    Fructose and leptin are clearly also involved, as are undoubtedly many other hormones and enzymes, but I like what Richard Feinman says, 'Lower GI or lower fructose? How to do both without saying “low-carbohydrate” out loud? This tangled web is woven out of the failure to face scientific fact…'
    I seem to remember Gary Taubes saying something to the effect, 'A lot of science needs to be done yet, but in the meantime I'm probably going low carb.'
  6. chris c
    Also works in Type 2. I have probably never had a proper Phase 1 insulin response to food but can seemingly produce endless Phase 2 insulin, just not at a high rate. Also I used to have high IR yet without being overweight (not uncommon).

    My BG would shoot up on eating an appreciable quantity of carbs, then drop precipitously two to four hours later when the insulin failed to shut down properly. This causes carb cravings which are not only quantitatively but qualitatively different from "real hunger", and if ignored could actually cause me to fall over.

    For decades I "treated" this by eating carbs every couple of hours. The actual "cure" is to avoid the carbs, particularly at breakfast, avoid the BG spike and thus avoid the ensuing insulin spike and BG drop.

    Now I routinely go 5 - 8 hours and often ten or more hours without feeling any NEED to eat, then when the hunger does arrive it is genuine and not nearly so intense.

    Tell this to a dietician and they assume you are lying (with a few exceptions) and must be secretly eating three Weetabix.

  7. Amy
    I have had great success getting my own diabetes under control with LCHF and no medication. My FBGs are now consistently below 130 after only four months ( I still have much room for improvement ) My husband is also T2D and takes several medicines including insulin. Any time he tries to eat LCHF with me his blood sugar shoots up the next morning(FBG). I'm not sure what to do. He enjoys the food but is afraid to jump into it because of these spikes. Does anyone have suggestions? My theory is that his medication (he has not changed any dose) is causing the pendulum to swjng too far the other way...
  8. Amy
    I have had great success getting my own diabetes under control with LCHF and no medication. My FBGs are now consistently below 130 after only four months ( I still have much room for improvement ) My husband is also T2D and takes several medicines including insulin. Any time he tries to eat LCHF with me his blood sugar shoots up the next morning(FBG). I'm not sure what to do. He enjoys the food but is afraid to jump into it because of these spikes. Does anyone have suggestions? My theory is that his medication (he has not changed any dose) is causing the pendulum to swing too far the other way...

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