Book Review: S.P.E.E.D.

This book was sent to me by Matt Schoeneberger, who co-authored it with Jeff Thiboutot. Both have master's degrees in exercise science and health promotion. S.P.E.E.D. stands for Sleep, Psychology, Exercise, Environment and Diet. The authors have attempted to create a concise, comprehensive weight loss strategy based on what they feel is the most compelling scientific evidence available. It's subtitled "The Only Weight Loss Book Worth Reading". Despite the subtitle that's impossible to live up to, it was an interesting and well-researched book. It was a very fast read at 205 large-print pages including 32 pages of appendices and index.

I really appreciate the abundant in-text references the authors provided. I have a hard time taking a health and nutrition book seriously that doesn't provide any basis to evaluate its statements. There are already way too many people flapping their lips out there, without providing any outside support for their statements, for me to tolerate that sort of thing. Even well-referenced books can be a pain if the references aren't in the text itself. Schoeneberger and Thiboutot provided appropriate, accessible references for nearly every major statement in the book.

Chapter one, "What is a Healthy Weight", discusses the evidence for an association between body weight and health. They note that both underweight and obesity are associated with poor health outcomes, whereas moderate overweight isn't. While I agree, I continue to maintain that being fairly lean and appropriately muscled (which doesn't necessarily mean muscular) is probably optimal. The reason that people with a body mass index (BMI) considered to be "ideal" aren't healthier on average than people who are moderately overweight may have to do with the fact that many people with an "ideal" BMI are skinny-fat, i.e. have low muscle mass and too much abdominal fat.

Chapter 2, "Sleep", discusses the importance of sleep in weight regulation and overall health. They reference some good studies and I think they make a compelling case that it's important. Chapter 3, "Psychology", details psychological strategies to motivate and plan for effective weight loss.

Chapter 4, "Exercise", provides an exercise plan for weight loss. The main message: do it! I think they give a fair overview of the different categories of exercise and their relative merits, including high-intensity intermittent training (HIIT). However, the exercise regimen they suggest is intense and will probably lead to overtraining in many people. They recommend resistance training major, multi-joint exercises, 1-3 sets to muscular failure 2-4 days a week. I've been at the higher end of that recommendation and it made my joints hurt, plus I was weaker than when I strength trained less frequently. I think the lower end of their recommendation, 1 set of each exercise to failure twice a week, is more than sufficient to meet the goal of maximizing improvements in body composition in most people. My current routine is one brief strength training session and one sprint session per week (in addition to my leisurely cycle commute), which works well for me on a cost-benefit level. However, I was stronger when I was strength training twice a week and never going to muscular failure (a la Pavel Tsatsouline).

Chapter 5, "Environment", is an interesting discussion of different factors that promote excessive calorie intake, such as the setting of the meal, the company or lack thereof, and food presentation. While they support their statements very well with evidence from scientific studies, I do have a lingering doubt about these types of studies: as far as I know, they're all based on short-term interventions. Science would be a lot easier if short-term always translated to long term, but unfortunately that's not the case. For example, studies lasting one or two weeks show that low glycemic index foods cause a reduction in calorie intake and greater feelings of fullness. However, this effect disappears in the long term, and numerous controlled trials show that low glycemic index diets have no effect on food intake, body weight or insulin sensitivity in the long term. I reviewed those studies here.

The body has homeostatic mechanisms (homeostatic = maintains the status quo) that regulate long-term energy balance. Whether short-term changes in calorie intake based on environmental cues would translate into sustained changes that would have a significant impact on body fat, I don't know. For example, if you eat a meal with your extended family at a restaurant that serves massive portions, you might eat twice as much as you would by yourself in your own home. But the question is, will your body factor that huge meal into your subsequent calorie intake and energy expenditure over the following days? The answer is clearly yes, but the degree of compensation is unclear. Since I'm not aware of any trials indicating that changing meal context can actually lead to long-term weight loss, I can't put much faith in this strategy (if you know otherwise, please link to the study in the comments).

Chapter 6, "Diet", is a very brief discussion of what to eat for weight loss. They basically recommend a low-calorie, low-carb diet focused on whole, natural foods. I think low-carbohydrate diets can be useful for some overweight people trying to lose weight, if for no other reason than the fact that they make it easier to control appetite. In addition, a subset of people respond very well to carbohydrate restriction in terms of body composition, health and well-being. The authors emphasize nutrient density, but don't really explain how to achieve it. It would have been nice to see a discussion of a few topics such as organ meats, leafy greens, dairy quality (pastured vs. conventional) and vitamin D. These may not help you lose weight, but they will help keep you healthy, particularly on a calorie-restricted diet. The authors also recommend a few energy bars, powders and supplements that I don't support. They state that they have no financial connection to the manufacturers of the products they recommend.

I'm wary of their recommendation to deliberately restrict calorie intake. Although it will clearly cause fat loss if you restrict calories enough, it's been shown to be ineffective for sustainable, long-term fat loss over and over again. The only exception is the rare person with an iron will who is able to withstand misery indefinitely. I'm going to keep an open mind on this question though. There may be a place for deliberate calorie restriction in the right context. But at this point I'm going to require some pretty solid evidence that it's effective, sustainable, and doesn't have unacceptable side effects.

The book contains a nice bonus, an appendix titled "What is Quality Evidence"? It's a brief discussion of common logical pitfalls when evaluating evidence, and I think many people could benefit from reading it.

Overall, S.P.E.E.D. was a worthwhile read, definitely superior to 95% of fat loss books. With some caveats mentioned above, I think it could be a useful resource for someone interested in fat loss.

Magnesium and Insulin Sensitivity

From a paper based on US NHANES nutrition and health survey data (1):

During 1999–2000, the diet of a large proportion of the U.S. population did not contain adequate magnesium... Furthermore, racial or ethnic differences in magnesium persist and may contribute to some health disparities.... Because magnesium intake is low among many people in the United States and inadequate magnesium status is associated with increased risk of acute and chronic conditions, an urgent need exists to perform a current survey to assess the physiologic status of magnesium in the U.S. population.

Magnesium is an essential mineral that's slowly disappearing from the modern diet, as industrial agriculture and industrial food processing increasingly dominate our food choices. One of the many things it's necessary for in mammals is proper insulin sensitivity and glucose control. A loss of glucose control due to insulin resistance can eventually lead to diabetes and all its complications.

Magnesium status is associated with insulin sensitivity (2, 3), and a low magnesium intake predicts the development of type II diabetes in most studies (4, 5) but not all (6). Magnesium supplements largely prevent diabetes in a rat model* (7). Interestingly, excess blood glucose and insulin themselves seem to reduce magnesium status, possibly creating a vicious cycle.

In a 1993 trial, a low-magnesium diet reduced insulin sensitivity in healthy volunteers by 25% in just four weeks (8). It also increased urinary thromboxane concentration, a potential concern for cardiovascular health**.

At least three trials have shown that magnesium supplementation increases insulin sensitivity in insulin-resistant diabetics and non-diabetics (9, 10, 11). In some cases, the results were remarkable. In type II diabetics, 16 weeks of magnesium supplementation improved fasting glucose, calculated insulin sensitivity and HbA1c*** (12). HbA1c dropped by 22 percent.

In insulin resistant volunteers with low blood magnesium, magnesium supplementation for four months reduced estimated insulin resistance by 43 percent and decreased fasting insulin by 32 percent (13). This suggests to me that magnesium deficiency was probably one of the main reasons they were insulin resistant in the first place. But the study had another very interesting finding: magnesium improved the subjects' blood lipid profile remarkably. Total cholesterol decreased, LDL decreased, HDL increased and triglycerides decreased by a whopping 39 percent. The same thing had been reported in the medical literature decades earlier when doctors used magnesium injections to treat heart disease, and also in animals treated with magnesium. Magnesium supplementation also suppresses atherosclerosis (thickening and hardening of the arteries) in animal models, a fact that I may discuss in more detail at some point (14, 15).

In the previous study, participants were given 2.5 g magnesium chloride (MgCl2) per day. That's a bit more than the USDA recommended daily allowance (MgCl2 is mostly chloride by weight), in addition to what they were already getting from their diet. Most of a person's magnesium is in their bones, so correcting a deficiency by eating a nutritious diet may take a while.

Speaking of nutritious diets, how does one get magnesium? Good sources include halibut, leafy greens, chocolate and nuts. Bone broths are also an excellent source of highly absorbable magnesium. Whole grains and beans are also fairly good sources, while refined grains lack most of the magnesium in the whole grain. Organic foods, particularly artisanally produced foods from a farmer's market, are richer in magnesium because they grow on better soil and often use older varieties that are more nutritious.

The problem with seeds such as grains, beans and nuts is that they also contain phytic acid which prevents the absorption of magnesium and other minerals (16). Healthy non-industrial societies that relied on grains took great care in their preparation: they soaked them, often fermented them, and also frequently removed a portion of the bran before cooking (17). These steps all served to reduce the level of phytic acid and other anti-nutrients. I've posted a method for effectively reducing the amount of phytic acid in brown rice (18). Beans should ideally be soaked for 24 hours before cooking, preferably in warm water.

Industrial agriculture has systematically depleted our soil of many minerals, due to high-yield crop varieties and the fact that synthetic fertilizers only replace a few minerals. The mineral content of foods in the US, including magnesium, has dropped sharply in the last 50 years. The reason we need to use fertilizers in the first place is that we've broken the natural nutrient cycle in which minerals always return to the soil in the same place they were removed. In 21st century America, minerals are removed from the soil, pass through our toilets, and end up in the landfill or in waste water. This will continue until we find an acceptable way to return human feces and urine to agricultural soil, as many cultures do to this day****.

I believe that an adequate magnesium intake is critical for proper insulin sensitivity and overall health.


* Zucker rats that lack leptin signaling

** Thromboxane A2 is an omega-6 derived eicosanoid that potently constricts blood vessels and promotes blood clotting. It's interesting that magnesium has such a strong effect on it. It indicates that fatty acid balance is not the only major influence on eicosanoid production.

*** Glycated hemoglobin. A measure of the average blood glucose level over the past few weeks.

**** Anyone interested in further reading on this should look up The Humanure Handbook

Dissolve Away those Pesky Bones with Corn Oil

I just read an interesting paper from Gabriel Fernandes's group at the University of Texas. It's titled "High fat diet-induced animal model of age-associated obesity and osteoporosis". I was expecting this to be the usual "we fed mice industrial lard for 60% of calories and they got sick" paper, but I was pleasantly surprised. From the introduction:

CO [corn oil] is known to promote bone loss, obesity, impaired glucose tolerance, insulin resistance and thus represents a useful model for studying the early stages in the development of obesity, hyperglycemia, Type 2 diabetes [23] and osteoporosis. We have used omega-6 fatty acids enriched diet as a fat source which is commonly observed in today's Western diets basically responsible for the pathogenesis of many diseases [24].

Just 10% of the diet as corn oil (roughly 20% of calories), with no added omega-3, on top of an otherwise poor laboratory diet, caused:

• Obesity
• Osteoporosis
• The replacement of bone marrow with fat cells
  
• Diabetes
• Insulin resistance
  
• Generalized inflammation
• Elevated liver weight (possibly indicating fatty liver)
  

Hmm, some of these sound familiar... We can add them to the findings that omega-6 also promotes various types of cancer in rodents (1).

20% fat is less than the amount it typically takes to make a rodent this sick. This leads me to conclude that corn oil is particularly good at causing mouse versions of some of the most common facets of the "diseases of civilization". It's exceptionally high in omega-6 (linoleic acid) with virtually no omega-3.

Make sure to eat your heart-healthy corn oil! It's made in the USA, dirt cheap and it even lowers cholesterol!