Questions and Answers: Dr. David LudwigDecember 29, 2015 Written by JP [Font too small?]
This is a follow up to my recent review of Always Hungry?, Dr. David Ludwig’s powerful, new diet and wellness book. In today’s blog, Dr. Ludwig is kind enough to clarify and expound upon some key points he originally made in the book. Specifically, I asked questions on the subjects I thought you would be interested in knowing more about. But, if I missed something, please let me know in the comment section below. I’ll do my best to get the answers. Lastly, before delving into the Q&A, I’d like to point out the above photo. Dr. Ludwig is seated next to his talented wife, Dawn Ludwig, a gourmet, natural health chef and creator of the delicious recipes contained in the book.
Q: In the Always Hungry Solution (AHS) you emphasize the pivotal role of insulin sensitivity in establishing and maintaining a healthy weight. What did you find in the AHS pilot study in terms of changes in fasting blood sugar and HbA1c? How about measures of inflammation, like C-reactive protein?
A: We didn’t conduct blood testing in the pilot for logistical reasons. However, we and many other research teams have looked at the effects of reducing total carbohydrate and/or glycemic index on these parameters. For example, in our JAMA 2012 feeding study, both the very low and moderate carbohydrate groups showed substantial benefits compared to the high carbohydrate group for liver and systemic insulin sensitivity and other components of the metabolic syndrome.
CRP was a bit discrepant, in that the very low carbohydrate group showed a tendency to be higher, and this may have related to the high saturated fat content. Clearly, saturated fat isn’t the public health enemy it has been made out to be for most of the last half century. But, too much of certain kinds of saturated fat for some people can be inflammatory – there’s clear mechanistic support for this possibility in animal studies and short term human studies. In any event, we don’t know whether the suggestion of an increase in inflammation on the very low carbohydrate diet is transient, and much more research is needed into this issue. With its moderate (but not low) saturated fat intake, the AHS aims to find a middle path – though the program is designed for individualization. For example, individuals with more severe insulin resistance may do best staying on Phase 1 of the program, which has a low carbohydrate level of 25%.
Q: Regarding blood sugar, do you think the use of a glucometer is a valuable adjunct to longer term blood work and the AHS worksheets?
A: Blood sugar monitoring is certainly important for people with diabetes (type 1 or 2), to determine proper medication dosing and avoid postprandial hyperglycemia. For everyone else, a general sense of carbohydrate tolerance can be useful to help establish parameters for total and processed carbohydrate intake.
The biohackers among us may like to collect information on blood glucose throughout the day. But one day won’t provide a complete picture, so this can be a laborious process. For the rest of us, a HgA1c test will provide a good guidepost. Those with levels approaching 6% may do best with relatively less carbohydrate – at least initially. We recently published in the journal Obesity evidence that the tolerance for carbohydrate can be improved – and the activity of insulin-producing pancreatic beta-cell in effect reset – after just one month of carbohydrate restriction.
Q: What’s your perspective on the recent popularity of ancestral type eating plans, such as those that approximate the Paleolithic diet?
A: The Paleo diet has become popular among a health-conscious segment of the population, and there’s much to recommend this approach. First and foremost, this diet eliminates all fast acting carbohydrates, which humans never ate until recently in our evolution (with the exception of honey, which was a favorite when it could be found).
One unresolved issue is what level of animal versus plant protein is optimal – both for ourselves and our environment. The best epidemiology rather consistently suggests an advantage for vegetarian proteins, not only for weight control, but also prevention of cardiovascular disease and diabetes. But there are unresolved issues. Could there be down sides to consuming large amounts of tofu and beans, dominant sources of plant protein? Are the adverse effects of animal protein related to industrial vs grass fed animal rearing?
Of course, with 7 billion humans, we can’t all go back to Paleolithic lifestyles, even if it were the healthiest option. There aren’t enough wild animals nor range land to feed so many people that way. (Though it warrants mention that in some environments, grazing animals are less disruptive to the ecology than farming.) Ultimately, we need more and better research, so that we can make the best decisions to balance our individual health and that of the environment upon which we all depend.
Q: In my opinion, low carbohydrate diets have yet to receive the respect they deserve. After reading your book and acknowledgments, it seems that you value much of the ketogenic and low carb research. Is this an accurate assessment?
A: Humans have the evolutionary special ability to make ketones – allowing the brain to be fully nourished when carbohydrate intake is low and protein intake isn’t high. For individuals such as those with type 2 diabetes, a ketogenic diet may be the quickest and most effective way to reverse metabolic dysfunction. In fact, one study I’d love to do (with adequate funding) would be to compare bariatric surgery with a ketogenic diet in the treatment of new onset type 2 diabetes. The ketone beta-hydroxy butyrate may have additional benefits for cancer prevention and slowing down the aging process – perhaps explaining why fasting seems to be so protective.
But a ketogenic diet is challenging to maintain, especially in our modern food environment. To be done right, this diet requires frequent blood ketone monitoring. A metabolically bad place to be is with low ketones and inadequate dietary carbohydrate to supply glucose for the brain. Fortunately, for many people, such severe carbohydrate restriction isn’t necessary to reduce insulin resistance, chronic inflammation and body weight.
Q: In your book, you recommend supplementing with vitamin D3. Is there a dosage you typically suggest? Are you an advocate of 25-hydroxy vitamin D testing for use as a personalized guide? If so, what range of vitamin D is a good benchmark for cardiometabolic health and weight?
A: Dosage of vitamin D varies greatly among people, in substantial part due to genetically determined differences in metabolism. Doses of up to 8000 IU per day appear to be safe, and don’t lead to excessively high serum levels. (A day in the sun can lead to the endogenous production of twice that amount). Generally speaking, I would recommend periodic monitoring, not only for those taking high doses of vitamin D, but also for those not taking any. The serum normal range is generally taken as 30 to 80 ng/ml, with much debate regarding the optimal range. Pending the results of several major clinical trials, I generally aim for levels of 40 to 60 – similar to those of several studied hunter-gatherers populations.
People living in Northern latitudes and not getting regular sun exposure (especially during the Winter) typically need 2,000 to 5,000 IU per day to reach this range. In addition, I recommend the mammalian form of vitamin D (D3, cholecalciferol) rather than plant form (D2, ergocalciferol) because of its greater bioavailability and the possibility of broader biological activity. Vegetarian versions of D3 are now available.
Q: In Always Hungry?, you touch upon the topic of gut microbiota and suggest a few ways to increase the population of beneficial bacteria – dietary fiber, kefir/yogurt consumption, probiotic supplementation, etc. Do you think microbiota play a significant role in the realm of weight gain and loss?
A: The role of gut microbes in weight loss and chronic disease prevention is among the most interesting and controversial in the field today. In the laboratory, it’s clear that obesity can be “transplanted” by transferring feces from a heavy animal to a lean one. In humans, the microbiome has been associated with just about every chronic disease imaginable, from asthma to Alzheimers.
The three key dietary determinants are prebiotics, probiotics and polyphenols. Prebiotics are fiber and other poorly digestible substances in food upon which beneficial microbes feed. Probiotics are the beneficial microbes themselves, which can be consumed as a supplement or from naturally fermented foods. And polyphenols are plant substances that serve to control the growth of potential harmful bacteria. The AHS emphasizes these “Three Ps” to cultivate a healthy microbiome.
Selecting the right probiotic supplement can be an uncertain and expensive undertaking. Look for a supplement that is refrigerated (to maintain potency) and contains a minimum of 10 billion CFU (colony forming units) per pill. For specific indications, such as leaky gut syndrome, selection of tailored formulations can be guided by stool microbiome analysis. But for general purposes, aim to add naturally fermented foods – real sauerkraut, kimchi, kefir, natural yogurt – to your regular diet.
Q: You take a strict stance when it comes to artificial sweeteners. Just don’t use them. However, you are a bit more lenient when it comes to stevia. Please explain why. Do you feel the same about monk fruit (Siraitia grosvenorii)?
A: Artificial sweeteners don’t have calories, yet they interact with our sweet taste receptors hundreds to thousands of times more powerfully than sugar itself. Of particular concern, sweet taste receptors are located not only in the mouth, but also throughout the digestive track and even on the surface of fat cells. Could these artificial chemicals have adverse metabolic effects, despite their lack of calories? Some concerning research suggests so. Stevia and a few other natural extracts have some track record of safe use, but we don’t have long-term data on high dose consumption.
Our research (AJCN 2013) and the experience of pilot test participants suggest that cravings and even preference for sweetness changes very rapidly on the AHS. With the luscious, high fat foods on the meal plan, the nucleus accumbens (ground zero for craving and addiction in the brain) seem to turn off, and we lose interest in the sweetened stuff.
Low Glycemic & Low Carb Diets Increase Energy (Calorie) Expenditure
Source: JAMA. 2012 Jun 27;307(24):2627-34. (link)
Q: You’ve co-authored many studies on the health implications of a low glycemic load diet in comparison to a higher glycemic load diet. The results, in both of your experiments and others, have been somewhat inconsistent. Why do you think this is the case?
A: The vast majority of clinical trials studying any dietary factor have been of moderate to extremely low quality – with small participant number, short duration, few quality control, limited compliance and use of proxy outcome measures. Studies of glycemic index are no exception in this regard. Moreover, individuals may vary in their response to any dietary factor, based on background diet, what other foods get added or subtracted, genetic susceptibility and current metabolic health. That said, among the highest quality existing research – that is, using a feeding study design to assure compliance and following individuals for an adequate period of time – reduction of glycemic index/load has consistently shown benefits (including in our studies and the Diogenes multicenter study from Europe).
Ultimately, the field greatly needs better quality research and this requires better funding. Drug trials often have budgets reaching tens to hundreds of millions of dollars. The budget for most diet trials is 1% of that. It costs at least $1 billion to bring just one drug from the laboratory to market. It’s time we adequately invest in nutrition research, to decrease our dependence on drugs to manage chronic disease.
Q: Have you looked into the possibility that the food-insulin index may also influence overweight?
A: The insulin index is interesting, and has some utility in the laboratory. But insulin response to food doesn’t take into account a key variable: glucagon. Some proteins can stimulate as much insulin secretion as carbohydrates, but those macronutrients have different effects on metabolism. That’s because protein also elicits a vigorous glucagon response, which counterbalances the anabolic action of insulin. In contrast, high glycemic index carbohydrates suppresses glucagon, leading to a metabolic double whammy. For this reason, the blood sugar response to food is the most important measure of postprandial metabolic consequences, with the insulin response providing some additional insights.
Q: The AHS integrates mindfulness as part of a holistic approach to fine tune hunger and establish a “lower (body weight) set point”. Are there any other mind-body practices that are particularly useful as an adjunct – cognitive bias modification, hypnosis, Emotional Freedom Technique/thought field therapy, etc.?
A: In addition to diet, lifestyle factors can also influence the behavior of fat cells. Too much stress, too little sleep and not enough physical activity can promote insulin resistance and chronic inflammation. The AHS focuses on these three areas, to synergize with diet. Mindfulness has special benefit – including dietary choice, stress reduction, and in other areas. However, there are many new and ancient methods from which to choose, and we encourage readers to find practices that are effective and enjoyable for them.
Pre-orders for Always Hungry? are now being accepted here. If you order prior to January 5th, the official release date, you’ll receive three free gifts to help get you started.
Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!
Tags: Inflammation, Insulin, Ketogenic
Posted in Diet and Weight Loss, Interviews, Nutrition