Monday, March 31, 2014
A few years ago I wrote about a meatza made with lean ground beef and bison (). This post is about another kind of meatza, one that takes a lot less time to prepare. In fact, this one is very quick, and still very nutritious.
The recipe below is for a meal that feeds 3-6 people. If you are preparing this for an opinionated family, and you do not want to be accused of preparing “grilled ham and cheese” for them, you can always add some sautéed vegetables to the ham.
- Place 2 to 3 lbs of folded ham into a sheet pan. There is no need to coat the pan, as some of the water and fat in the ham will seep out and prevent sticking.
- Add some dry seasoning and butter. For the dry seasoning, I suggest a mix of garlic powder and cayenne pepper.
- Add a layer of genoa salami, and another layer of swiss cheese.
- Preheat oven to 375 degrees Fahrenheit.
- Bake the meatza for about 15 minutes.
The photo montage above shows the different stages of preparation and the final product. Since ham cuts tend to be very lean, the amount of fat in the entire meatza will normally depend heavily on the amount of added butter, salami, and cheese.
In this kind of meatza, the protein-to-fat ratio will normally be greater than 1. I think a ratio closer to 2 is ideal for those semi-sedentary office workers who do moderate exercise. The reason is that fat is the most calorie-dense macronutrient. Protein is the least calorie-dense macronutrient.
You do lose something with this dish, as you do with hot dishes in general. You lose the probiotic bacteria that would normally be found in significant amounts in the ham, salami, and cheese. These are all fermented foods that are better consumed raw.
Tuesday, March 18, 2014
Doing resistance exercise to failure is normally recommended for those who want to maximize strength and muscle mass gains from the exercise. Yet, going to failure tends to significantly increase the chances of injury, after which the ability to do resistance exercise is impaired – also impairing gains, in the long term.
From an evolutionary perspective, getting injured is clearly maladaptive. Prey animals that show signs of injury, for example, tend to be targeted by predators. There is also functional loss, which would be reflected in impaired hunting and gathering ability.
So, assuming that going to failure is at least somewhat unnatural, because of a higher likelihood of subsequent injuries, how can it be advisable in the context of resistance exercise?
The graph below is from a study by Izquierdo and colleagues (). They randomly assigned several athletes to two exercise conditions, namely resistance training to failure (RF) and not to failure (NRF). A control group of athletes did not do any resistance exercise. The athletes were tested at four points in time: before the initiation of training (T0), after 6 wk of training (T1), after 11 wk of training (T2), and after 16 wk of training (T3).
The graph above shows the gains in terms of weight lifted in two exercises, the bench press and squat. It is similar to other graphs from the study in that it clearly shows: (a) improvements in the amount of weight lifted over time for both the RF and NRF groups, which reflect gains in strength; and (b) no significant differences in the improvements for the RF and NRF groups.
When you look at the results of the study as a whole, it seems that RF and NRF are associated with slightly greater or lesser gains, depending on the type of exercise and the measure of gains employed. The differences are small, and one can reasonably conclude that no significant difference in overall gains exists between RF and NRF.
It is clear that going to failure leads to increased metabolic stress, and that increased metabolic stress is associated with greater secretion of anabolic hormones (). How can this be reconciled with the lack of a significant difference in gains in the RF and NRF groups?
The graph below provides a hint as to the answer to this question. It shows resting serum cortisol concentrations in the participants. As you can see, after 16 wk of training (T3) cortisol levels are higher in the RF group, which is particularly interesting because the NRF group had higher cortisol levels at baseline (T0). Cortisol is a catabolic hormone, which may in this case counter the effects of the anabolic hormones, even though going to failure is expected to lead to greater anabolic hormone secretion.
It seems that cortisol levels tend to go up over time for those who go to failure, and go down for those who do not. I am not sure if this is a strictly metabolic effect. There may be a psychological component to it, as strength and power gains over time tend to be increasingly more difficult to achieve (see schematic graph below); perhaps leading to some added mental stress as well, as one tries to continue increasing resistance (or weight) while regularly going to failure.
And, of course, it is also possible that the results of the study reviewed here are a statistical “mirage”. The authors explain how they controlled for various possible confounders by adjusting the actual measures. This approach is generally less advisable than controlling for the effects of confounders by including the confounders in a multivariate analysis model ().
Nevertheless, in light of the above I am not so sure that regularly doing resistant exercise to failure is such a good idea.
Wednesday, March 5, 2014
The health effects of very-low-calorie diets (VLCDs) adopted for short periods of time (e.g., 5 days) have been the target of much recent in the past. Consuming 400-600 kcal/day would be considered VLCDing. VLCDing for significantly longer periods of time than 5 days can be dangerous, and in some cases potentially fatal. Nevertheless, there is speculation that it can also cure type II diabetes ().
Intermittent VLCDs mimic in part what probably happened with our ancestors in our evolutionary past. Successful hunting and gathering would lead to weight-maintenance food intake most of the time, with occasional periods of severe food scarcity. This has probably been a regular pattern in our evolutionary history, leading to health-promoting adaptations that are triggered by VLCDs.
The part that VLCDs alone do not mimic is the “hunting and gathering part”, or the exercise required to obtain food when it is scarce. This is an important point, because VLCDs are likely to induce lean body mass loss without exercise, together with body fat loss. VLCDs without exercise are not very natural, even though they can have very positive effects on one’s health, as we’ll see below.
An interesting and well cited study of the effects of VLCDs in participants with type II diabetes was published in 1998 in an article authored by Katherine V. Williams and colleagues (). The study included 54 participants, and lasted 20 weeks in total. The site of the study was the University of Pittsburgh School of Medicine. The participants were split in three groups, referred to as:
- Standard behavioral therapy (SBT). The participants received a 1,500−1,800 kcal/day diet throughout, with the goal of inducing gradual weight loss.
- Intermittent 1 day/week VLCD (one-day). The participants received a VLCD for 5 consecutive days during week 2, followed by an intermittent VLCD therapy for 1 day/week for 15 weeks, with a 1,500−1,800 kcal/day diet at other times.
- Intermittent 5 day/week VLCD (five-day). The participants received a VLCD for 5 consecutive days during week 2, followed by an intermittent VLCD therapy for 5 consecutive days every 5 weeks (5-day), with a 1,500−1,800 kcal/day diet at other times.
There is a reason behind this complicated arrangement. The researchers wanted to make sure that the average caloric intake for the two VLCD groups was identical, but 18,000-28,000 kcal lower than for the SBT group. The SBT group served as a baseline group.
All of the three diets were designed to make the participants lose weight. Exercise was not manipulated as part of the experiment. The one-day and five-day groups consumed 400-600 kcal/day while VLCDing, with the majority of the calories coming from high-protein-low-fat minimally processed food items – notably lean meat, fish, and fowl.
The graphs below show results in terms of weight loss and fasting plasma glucose (FPG) reduction. They suggest that, while there were significant differences in weight loss between the VLCD groups and the SBT group, the differences in FPG reduction were relatively minor across the three groups.
Glucose was measured in mmol/l and weight in kg. One mmol/l is equivalent to approximately 18 mg/dl (), and one kg is equivalent to about 2.2 lbs.
The graph below, however, shows a different picture. It shows results in terms of the percentages of participants with HbA1c below 6 percent. The HbA1c is a measure of average blood glucose over a period of a few months ().
The graph above tells us that the intermittent VLCD interventions, particularly the second (five-day), were reasonably successful at promoting average blood glucose control. A threshold normally used to characterize poor blood glucose control is 7.3 percent (), which is based on studies of HbA1c levels associated with diabetes complications.
The graph below, which is probably the most telling of all, shows long-term FPG changes (at the 20-week mark) plotted against short-term changes (at the 3-week mark). What this graph tells us is that those who experienced the most improvement right away were the ones with the most improvement in the long term.
This study tells us a few interesting things. Firstly, intermittent VLCDing with a focus on high-protein foods (lean meats) seems to be a powerful way of controlling average blood glucose levels in diabetics. It is essentially a low carbohydrate diet that is also low in calories (). Secondly, results with respect to FPG levels are not as telling as those in terms of HbA1c levels, even though HbA1c and FPG are highly correlated.
Thirdly, intermittent VLCDing may not actually “cure” diabetes when significant beta cell damage has already occurred (). This conclusion is speculative, but it follows from the short-term versus long-term results.
It seems that intermittent VLCDing helps diabetics in general with glucose control, but is truly curative for those in which enough beta cell function has been preserved. At least this is one explanation for the fact that those with immediate positive results (at the 3-week mark) tend to be the ones who retain those results over the long term.
The immediate positive results may well be due to those individuals not having reached the point at which significant and irreversible beta cell damage occurred. In other words, this study suggests that intermittent VLCDing can be particularly helpful in the long term for prediabetics.
This third, and speculative, conclusion may have to be revisited in light of the excellent discussion by Roy Taylor on the etiology and reversibility of type II diabetes (), linked by Evelyn (see comments under this post). This refers to the effects of an extended and more extreme version of VLCD than discussed here, where uninterrupted VLCD would last as long as 8 weeks.
For those who are not diabetic, I personally think it would be better to alternate VLCD with glycogen depleting exercise (e.g., sprints, weight training), every other day or so, with a lot more food consumed on exercise days (). After excess body fat is lost, it would be advisable to stick to weight-maintenance calorie intake, averaged over a week.
Monday, February 17, 2014
Typically obesity leads to health problems via insulin resistance (). Excess calories are stored as fat in fat cells up to a certain point. Beyond this point fat cells start rejecting fat. This is the point where fat cells become insulin resistant.
When they become insulin resistant, fat cells no longer respond to the insulin-mediated signal that they should store fat. Fat then increases in circulation and starts getting stored in tissues other than fat cells, including organ tissues (visceral fat). When the organ in question is the liver, this is called non-alcoholic fatty liver disease.
This progression happens with most people, but not with those who can progress to extremely high body fat levels (). Those people are the “megafat-prone” (MP). In the MP, fat cells take a long time to start rejecting fat. So the MP can keep on gaining body fat, often with no sign of diabetes at body fat levels that would have caused serious harm to most people.
One could say that the MP are extremely metabolically resilient. By not becoming insulin resistance as they gain more and more body fat, the MP are somewhat similar to sumo wrestlers (photo below from Nationalgeographic.com); although the main reason why sumo wrestlers do not develop insulin resistance is vigorous exercise. Visceral fat is very easy to "mobilize" through vigorous exercise; this being the basis for the "fat-but-fit" phenomenon (). There are two interesting, and also speculative, inferences that can be made based on all of this.
One is that the MP could potentially be the healthiest people among us. This is due to their extreme metabolic resilience, which should be fairly protective if they can avoid getting up to the unhealthy point of body fat for them. In fact, they could be overweight or even obese and fairly healthy, at least in terms of degenerative diseases. This is a genetic predisposition, which is likely to run in families.
The other inference is that the MP would probably not look “ripped” at relatively low weights. Since their body fat cells have above average insulin sensitivity at high body fat levels, one would expect that high insulin sensitivity to remain at low body fat levels. Insulin sensitivity is strongly associated with longevity ().
So, bringing all of this together, here are two apparent paradoxes. That person who already gained a lot of body fat and is an MP, showing no health problems at or near obesity, could be the healthiest among us. And that person who cannot look ripped at low body fat levels, no matter how hard he or she tries, may be one of the 2 percent or so of the population who will live beyond 90.
Unfortunately it is hard to tell whether someone is MP or not until the person actually becomes megafat. And if you are MP and actually become megafat, the afterlife will very likely arrive sooner rather than later.
Monday, February 3, 2014
I have posted here before about the nutrition value of beef liver, nature’s “super-multivitamin”. I have even speculated that grain-fed beef liver could be particularly nutritious (). What I should have done also was to post about beef liver’s equal in terms of nutrition value – beef heart. In this post I am correcting the omission.
Contrary to popular belief, not all organ meats are inherently fatty. The fat that is attached to an animal’s heart after slaughter, even if from grain-fed cattle, can be easily removed. The resulting cut will have a very low fat-to-protein ratio; often significantly less than fat-trimmed non-organ muscle cuts.
I don't say this because I consider fat to be unhealthy. In fact, dietary fat is necessary for the absorption of fat-soluble vitamins, and can thus be uniquely healthy. However, fat also is the most calorie-dense macronutrient. Even though the caloric values of macronutrients vary based on a number of factors, excess calories tend to be stored as excess body fat.
A 100 g portion of cooked beef heart, as in the photos below, will have 28 g of protein and only 5 g of fat (see this link, you may have to reset the serving size field: ). The photos below show two different beef heart dishes I have prepared. In the first the beef heart was barbecued. In the second it was simmered in a pan with vegetables for about 8 h.
Below is a simple recipe for the barbecued beef heart, which I recommend cutting into steaks. For the simmered beef heart I suggest cutting it into chunks that resemble cubes; then you can just add the dry seasoning powder mentioned below to the water, some vegetables, enough water to last about 8 h, and leave it simmering.
- Prepare some dry seasoning powder by mixing salt, garlic power, chili powder, and a small amount of cayenne pepper.
- Season the beef heart steaks at least 2 hours prior to placing them on the grill.
- Grill with the lid on, checking the meat every 10 minutes or so. (I use charcoal, one layer only to avoid burning the surface of the meat.) Turn it frequently, always putting the lid back on.
- If you like it rare, 20 minutes (or a bit less) may be enough.
Beef heart is a very good source of vitamins and minerals, and is one of the least expensive cuts of meat (in meat sections of grocery stores, not in paleo restaurants). Many people prefer beef heart over beef liver because of beef heart’s texture.
While I have restricted my comments in this post to “beef” heart, the hearts of most animals that are eaten by humans (e.g., chicken, duck, deer, turkey) are fairly nutritious, and they seem to have that uniformly meaty texture that many people like.
Here is an interesting factoid. The largest known carnivorous marsupial of modern times was the now extinct Tasmanian tiger. It was an elusive and solitary animal, and the subject of the beautiful film "The Hunter (2001)" (). The Tasmanian tiger was known to frequently eat only the hearts of prey. I hope this is not why it became extinct!
Tuesday, January 21, 2014
The optimal waist / weight ratio (WWR) theory () is one of the most compatible with evidence regarding the lowest mortality body mass index (BMI).
But why do we need the WWR when we already have the BMI? This was a question that a reader asked me in connection with a post on the John Stone transformation ().
The montage below shows photos of the John Stone transformation with the respective WWR and BMI measures.
Well, which one is the most useful measure, WWR or BMI?
Monday, January 6, 2014
Top crossfit athletes like Annie Thorisdottir and Rich Froning Jr. (pictured below; photos from Crossfitthestables.com and List09.com) look like bodybuilders even though their training practices are markedly different from those of most top natural bodybuilders. It is instructive, from a human physiology perspective, to try to understand why.
First of all we should make it clear that what makes Annie Thorisdottir and Rich Froning Jr. look the way they do is not only crossfit training. Genetics plays a key role here. Some people don’t accept this argument at all. Can you imagine someone arguing that top basketball players are generally tall because the stretching and reaching moves inherent in playing basketball make them tall? Top basketball players are not tall because they play basketball; the causality is stronger in the opposite direction: they play basketball because they are tall. The situation is not all that different with top crossfit competitors.
Often people will point at before and after photos as evidence that anyone can achieve the level of muscularity of a champion natural bodybuilder, if they do the right things. The problem with these before and after photos is that one can “go down” in terms of muscularity and definition quite a lot, but there is a clear ceiling in terms of “going up”. For example, if one goes from competitive marathon running to competitive bodybuilding, after a few years the difference will be dramatic if the person has the genetics necessary to gain a lot of muscle.
In other words, those who have the genetics to become very muscular can lose muscle and/or gain body fat to the point that they would look like they don’t have much genetic potential for muscle gain. Someone who doesn’t have the required genetics, on the other hand, will also be very effective at losing muscle and/or gaining body fat, but will be much more limited at the upper end of the scale.
The table below is from a widely cited and classic study by Fryburg and colleagues on the effects of growth hormone, insulin, and amino acid infusion on muscle accretion of protein. The article is available online as a PDF file (). The measurements shown on the table were taken basally (BAS) and at 3 h and 6 h after the start of the infusions, one of which was of a balanced amino acid mixture that raised arterial phenylalanine concentration to about twice what it was before the infusion. Phenylalanine is one of the essential amino acids present in muscle ().
There were four experimental conditions, two with only amino acid infusion, one with insulin and amino acid infusions, and one with insulin-like growth factor 1 (IGF-1) and amino acid infusions. Protein synthesis and breakdown numbers are based on phenylalanine kinetics inferences. The balance number is based on the synthesis and breakdown numbers; the former minus the latter. Note that at BAS the balance is always negative; this implies a net amino acid loss from muscle. At BAS the measurements were taken after a 12 h fast.
All infusions – of insulin, IGF-1, and amino acids – were continuously applied during the 6 h period. There was no exercise involved in this infusion study, and the amino acid mixture was balanced; as opposed to focused on certain amino acids, such as BCAAs.
The numbers in the table suggest that insulin infusion brings the balance to positive territory at the 3-h mark, with the effect wearing down at 6 h. IGF-1 infusion brings the balance to positive territory at 3 h, with the effect increasing and almost doubling at 6 h. Amino acid infusion alone brings the balance to positive territory a bit at 3 h and 6 h, and much less than when it is combined with insulin or IGF-1 infusions.
The effects of these infusions were due to both reductions in breakdown (amino acid loss) and increases in synthesis. We see that insulin exerts its effect on the balance primarily by suppressing breakdown. IGF-1 exerts its effect on the balance primarily by increasing synthesis. The effect of IGF-1 on the balance is significantly stronger than those of insulin and amino acid infusions, even when these latter two are taken together.
While this is an infusion study, one can derive conclusions about what would happen in response to different types of exercise and nutrients. Under real life conditions, insulin will increase in response to ingestion of carbohydrates and/or protein. IGF-1 will increase in response to growth hormone (GH) elevation, of which a major trigger is intense exercise.
The type of exercise that leads to the highest elevation of GH levels is intense exercise that raises heart rate significantly and rapidly. Examples are sprints, large-muscle resistance exercise, and resistance exercise involving multiple muscles at the same time. At the very high end of GH secretion are exercises that use large upper and lower body muscles at the same time, such as the deadlift. At the low end of GH secretion are localized small-muscle exercises, such as calf raises and isolated curls.
Anecdotally it seems that, at least for beginners, those exercises that lead to the highest GH secretion are the least “comfortable” for them. That is, those are the exercises that cause the most “huffing and puffing”. So next time you do an exercise like that, use this as a motivator: these are the exercises with the biggest return on investment; whether you are looking for health improvement, muscle gain, or both.
Competitive crossfit practitioners tend to favor variations of high-intensity interval training (HIIT), with an emphasis on a blend of endurance and strength exercises. Endurance and strength are both needed in crossfit competition. Competitive bodybuilders tend to focus more on strength, often exercising with more resistance or weight than competitive crossfit practitioners.
Extrapolating from the infusion study, one could argue that high GH secretion exercises are critical for amino acid accretion in muscle. Both groups mentioned above – competitive crossfit practitioners and competitive bodybuilders – exercise in ways that lead to high GH secretion. Surprising as this may sound (to some), if you do chin-ups, you’ll probably have better results in terms of biceps hypertrophy than if you do isolated bicep curls. This will happen even though the overall load on the bicep muscles will be lower with the chin-ups. The reason is that the GH secretion will be significantly higher with the chin-ups, because more muscles are involved at the same time, including large ones (e.g. the lats).
It is interesting to see competitive crossfit practitioners talking about needing to lose some weight but not being able to (). The reason is that they do not have much body fat to lose, and the types of exercise that they do create such a powerful stimulus toward positive nitrogen balance () that they end up gaining weight even as they restrict calorie intake.
Carbohydrate ingestion prior to exercise may raise insulin levels, but will blunt GH secretion; protein without carbohydrate, on the other hand, will raise insulin levels without blunting GH secretion (). Whether ingesting protein immediately before exercising is necessarily good in the long run is an open question, however, because GH secretion is likely to be greater for someone who is exercising in the fasted state, as GH secretion is in part a response to glycogen depletion (, ). And, as we have seen from the infusion study, GH secretion is disproportionately important as a positive nitrogen balance factor.
Compensatory adaptation applied to human biology () suggests that the body responds to challenges over time, in a compensatory way. Which scenario poses the bigger challenge: (a) high GH exercise with more amino acid loss during the exercise, or (b) high GH exercise with less amino acid loss during the exercise? I think it is (a), because the message being sent to the body is that “we need more muscle to do all of this and still compensate for the loss during exercise”.
Maybe this is why top crossfit practitioners end up looking like bodybuilders, and cannot lose muscle even when a slightly lighter frame would make them more competitive in crossfit games. Their bodies are just responding to the stimuli they are getting.