Introduction – Fat Is Beautiful?
While you T-men and T-ixens may find this difficult to believe, once upon a time, fat was not abhorred the way it is today. In fact, to be plump (not obese, of course) was viewed as a status symbol. Carrying around a bit of excess body fat distinguished the nobility from the peasantry and therefore became a sign of attractiveness, of beauty. But let's be honest. Back then, stripped down to the most basic of levels, being fat meant that you could afford to eat!
To illustrate this, here are a couple of interesting ideas that came about just before the turn of the century:
In the 1880's photographers were instructed that models "with hollowed cheeks or visible collar-bones" should not be photographed because the camera would accentuate these "defects."
In addition, in 1882, Americans discouraged exercise, as they believed that it "would burn excessive amounts of fat."
But in the late 1800's and early 1900's when industrialization took over and food became easily available, even the lower and middle classes could afford to become plump. Well, this certainly aggravated the upper class, as they no longer could be distinguished by their rounded physiques. In an effort to differentiate themselves from the lower and middle classes, they decided to adopt a new ideal, and slim was now in.
The irony of it all is that as a result of this new ideal, healthy food was in demand, and much the same as it is today, eating well became expensive. So what happens is that the lower and middle classes can hardly afford to be thin, while in the 1800's they could hardly afford to be fat.
So with this new standard in beauty and refinement set, the weight-loss industry began and people began to worry about losing weight (at first) and (more recently) about losing fat.
So with that said, the objective of this two part article (which served as the transcript from the second of two, 2-hour lectures I recently gave at Ian King's excellent "Bigger, Stronger, Leaner!" seminar in Toronto) is to:
1. Give you a brief interesting history of the weight loss industry.
2. Present a review of the effectiveness of different weight/fat loss strategies.
3. Present a model for designing healthy and effective weight/fat loss strategies.
The Weight Loss Industry – A Checkered Past
As is the case with any dramatic shift in public opinion, new problems arise which require new solutions. About the turn of the century the new problem was how to lose weight. And the weight loss industry exploded in offering solutions. However, in the absence of detailed scientific data on the nature of energy balance, food composition, and the cellular mechanisms of energy exchange, the best the industry could do was search for agents that promoted weight loss, regardless of how they worked. Here are a few frightening examples of this mentality in action.
When I say the words, "heroin chic," you think of the waif supermodels that believe heroin is the best diet drug available. Well, back in the dawn of the diet age, they had their own version of heroin chic that we'll affectionately call "consumption chic." You see, at the time, several popular European poets and writers (Keates, Shelly, Chekov, Bronte) had tuberculosis, which made them sickly and thin. People therefore associated this look with refinement and intelligence. As a result, the wealthy, taking the lead of other celebrities of the day, began starving themselves to appear sickly and refined. And the very low calorie diet (VLCD) was born.
When I was growing up, a popular statement in my house was "John, I can't afford you eating like this; whadda' ya' have, a hollow leg or a tapeworm or something?" Now I didn't know what a tapeworm was (a worm made out of masking tape?), but I associated it with being able to eat a lot of food while staying thin, so the tapeworm was okay with me. But going back to the turn of the century, a popular question of the day might have been "Where can I get some chocolate covered tapeworms?" Yep, tapeworms (parasites that live in the intestinal tract) were actually used as a way to lose weight!
During this same time period, even Kellogg of cereal fame entered the diet market by offering their "Safe Fat Reducer." This product was loaded with thyroid hormone. And not the kind that comes nicely sterile as synthesized by a pharmaceutical laboratory. No, they added the pulverized thyroid glands of dead animals to their product.
Other common ingredients that were used in the tonics introduced during the infancy of the diet industry were laxatives (cause diarrhea), purgatives (cause vomiting), strychnine (cause nervousness, restlessness, tremors), and arsenic (cause death – Do you weigh less when you're dead?).
Getting even further away from the scientific method, some "diet experts" had a theory that men and women should not use lotions or cosmetics. In their opinion, these agents were absorbed into the skin, transported to fat cells, and stored as body fat. This was not good news for Oil Of Olay.
A final interesting diet drug note concerns our old friend DNP. For those of you who don't know, DNP (dinitrophenol) gained popularity in the 1990's as a particularly effective fat-loss drug among bodybuilders. But DNP was nothing new; in fact, it was the very first drug ever prescribed for weight loss. By 1935, over 100,000 Americans had taken DNP to lose weight. So where can you get some? Not so fast. The problem is, DNP was actually found to be an effective agent for promoting weight loss in munitions plants during WWI. What happened was that fat munitions workers who had been exposed to DNP (which is used commercially in explosives, as an herbicide, and an insecticide) were losing huge amount of weight.
What they didn't know at the time though, was that the physiological actions of DNP cause the body to uncouple oxidative phosphorlylation from ATP production. In essence, normally, people metabolize food to produce energy (ATP). Well, DNP causes the body to metabolize food but instead of producing energy (ATP), heat is generated; so much heat that the organs can actually cook in the body. So, if you don't mind liquefied organs, DNP will help melt away body fat, literally. And this was a popular diet treatment!
The Weight Loss Industry – The Focus on Food
Although low carb diets (i.e. ketogenic diets and the Atkins Diet) have been in vogue for the last few years, let me shed a little light on where the concept of the low carb diet came from. Interestingly, the first low carb diet was promoted several years before we even had strong evidence that carbohydrates, fats, and proteins were present in our foodstuffs.
As legend has it, William Banting, a very overweight casket maker (of all things), was worried that his casket would be too expensive to fit his large, gelatinous physique. So he theorized that eating less starch (potatoes, bread, pasta) would help him lose weight. And right he was as he dropped down a few "casket sizes." He became slim and svelte and in 1878 he published his "Letter on Corpulence," extolling the virtues of the no bread, no potatoes, and no pasta diet. So the first low-carb diet came from a casket maker.
Just a few years later, information began trickling out of the scientific community regarding the composition of food. In the 1890's Wilber Atwater is credited for observing the different macronutrient components of food. In the early 1900's, Russell Chittenden went a step further to determine the calorie content of food. With these data, the concept of energy balance and the practice of calorie counting was born.
Half a century later, in the 1950's, the research world began to publish extensively on different diet strategies including ketogenic diets, high protein diets, very low calorie diets, and protein sparing modified fasts; this last one known to T-mag readers as "Fat Fast." As a result of these dietary strategies, rather than promoting long-term weight loss, the concept of yo-yo dieting began.
So, T-men and vixens, take note. While writers are often "introducing new diet plans," there is very little that is "new." As mentioned, the "Fat Fast" diet was popular in the 1950's (although Brock's version has a few modifications that make it a bit better), ketogenic diets were used at the same time with limited success, and even the Atkins diet was first introduced in 1966. So don't fall victim to the notion that these diets are really revolutionary ways to lose fat. As you're about to see, they failed miserably back then, and even now, they aren't the best way to change your physique.
Weight Loss Research
The problem with the dangerous early approaches to weight loss as well as the later diet approaches (including ketogenic diets, very low calorie diets, fat fast type diets, etc) is that they all worked to one degree or another but the effects of these treatments lasted only as long as the treatments were followed. In addition, since the focus was on weight loss (not fat loss), the composition of the loss (lean vs. fat) was usually ignored. Once the drugs were removed or normal dieting resumed, subjects actually gained more fat than they had lost!
Then comes research to the rescue. When more accurate methods of body composition testing were developed, body composition was used to determine the proportions of the loss. These new techniques demonstrated that most of the aforementioned low calorie diets decreased metabolic rate, chronically depleted muscle glycogen (and therefore performance), and decreased lean body mass (muscle).
Here are some of the more important research breakthroughs of the last couple of decades:
Studies by Elliot et al (1989) showed that a modified fast resulted in a 22% reduction in RMR and this persisted even 8 weeks after returning to a mixed, maintenance diet. This means that the metabolism can be chronically depressed after dieting, even when returning to a reasonable energy intake.
Coxon et al (1989) showed that diets resulting in a weight loss of 4.18 lbs per week lead to losses of 1.75 lbs of lean mass per week. Very bad!
Bogardus et al (1981) showed that a carbohydrate restricted diet (35%P, 1%C, 64%F - 850kcal) chronically decreased muscle glycogen by 50% and as a result, decreases exercise performance by 50% as compared to a carb containing isoenergetic diet (35%P, 36%C, 29%F - 850 kcal). No decreases were seen in the moderate carbohydrate group.
Dulloo et al (1990) showed that in calorie deprived (50% below maintenance) rats, weight regain was rapid and nearly all weight regained was fat. The muscle mass that was lost was not replenished with refeeding.
Therefore, in each of these studies, the prescribed diets lead to a smaller metabolic furnace and the dieters couldn't help but gain the fat back. As a result, researchers were looking for alternative ways of manipulating the energy balance equation (energy in – energy out). Enter aerobic exercise intervention.
In prescribing aerobic exercise, researchers believed that exercise would promote fat loss alone, enhance fat loss with dieting, and/or prevent metabolic decline with dieting. And they were correct. Nicklas et al (1997) and Dengel et al (1994) showed that when dietary treatment (300kcal below maintenance) was compared to dietary treatment plus aerobic exercise, the diet plus aerobic exercise group was more fit, retained more lean mass (but they still lost some), and lost more fat. In addition, in diet only groups, fat breakdown and oxidation tend to decline, but when adding aerobic exercise, fat breakdown and oxidation are not decreased.
Although aerobic exercise was effective for assisting in fat-loss programs, some lean mass is still lost. With the muscle building and preserving properties of weight training starting to be realized, finally, researchers began to speculate that another form of exercise might be beneficial in addition to aerobic exercise. Enter resistance exercise intervention:
Ballor et al (1988) studied 4 groups of subjects. The first group was a control; the second group ate below maintenance; the third group performed resistance training only; and the fourth group dieted and lifted. While the diet and the diet plus exercise groups lost the same amount of weight, the diet plus exercise group actually gained lean mass while the diet group lost lean mass. In addition, the exercise only group lost no weight but did increase lean mass substantially.
In a direct comparison of aerobic and resistance training, Kraemer et al (1999) showed that diet plus resistance exercise was better than diet alone or diet plus aerobic exercise in preserving lean body mass and muscle power during weight loss. All three groups lost a similar amount of weight but while the diet group lost 6 lbs of lean mass and the aerobic group lost 4 lbs of lean mass, the resistance group didn't lose any lean mass. This means that the resistance group also lost the most fat mass.
At this point in time, it's well recognized that a fat reduction strategy should include diet, aerobic, and resistance exercise strategies. Below, I've provided a list of what you might expect to happen with each treatment:
Aerobic exercise alone leads to a 3 lb weight loss in 12 weeks and a 6.6-lb weight loss in 30 weeks. This is accompanied by no losses in LBM (*at maintenance caloric intake).
Resistance exercise alone leads to no weight loss but a 2.2 lb (women) to 4.4 lb (men) gain in LBM in 8-12 weeks (*at maintenance caloric intake).
Diet alone leads to a 6.4 lb LBM loss for every 22 lbs weight lost.
Diet plus aerobic exercise leads to a 3.74 lb LBM loss for every 22 lbs weight lost
Diet plus resistance exercise leads to losses in fat mass and a preservation of LBM.
Conclusion – Research Summary
Based on what I've presented so far, here is a summary of what's happening with the different weight loss strategies.
1) Diet alone works for weight loss but it leads to unacceptable losses in metabolic rate and LBM.
2) Aerobic exercise alone can lead to comparable fat loss with diet conditions (assuming the same energy deficit). However it's difficult to burn the required amount of calories for sufficient weight loss with aerobic exercise. In addition, if adequate exercise is performed for a reasonable fat loss, some lean body mass may also be lost.
3) Resistance exercise alone cannot match diet-induced weight loss.
4) Simultaneous exercise and diet interventions do not necessarily lead to greater weight loss than diet alone, but energy metabolism is improved and lean-body mass is preserved.
5) A combination of diet, a small amount aerobic exercise, and moderate amount of resistance exercise should yield the greatest weight loss while preserving LBM.
Looking back through this article, it appears that we've come a long way in our quest to lose fat. However, while researchers are doing quite a bit to promote healthy weight loss, let's not lose sight of where the diet industry is today. Are our current diet drugs completely safe and effective? That's debatable. How about our commercial weight loss clinics? Certainly not!
You know, although we can laugh at the ridiculousness of the diet industry of 100 years ago, these stories, in my opinion, serve as a warning for us. I often wonder what the articles in the year 2100 will say about us.
In next week's article, I plan on presenting some excellent diet and exercise strategies for dropping fat quickly and safely.