Nutrition Performance - Nutrition and Body Lardness
Just the Facts, Man
“That it took so many years to get a low-carbohydrate diet accepted as a possible thing to experiment on and talk about was a shock to us. The scientific community absolutely stonewalled that for so long, and we allowed them to stonewall it. It is a shame, and in a way, we’re both guilty, the stonewallers and the people who knew better but weren’t able to put up enough opposition to force the issue. I think congratulations are due because finally this has broken out into the ope, and it’s talked about, and there are studies done. It is a shame it took so long.”
— Dr. Jesse Roth
Albert Einstein College of Medicine
Obesity Research, 2004;12:147S
For way too many years, dietary guidelines for the treatment of obesity have advised a low-fat, high-carb diet. However, the “low-fat is the way to go” message has not impacted the ever increasing rates of lardness. Consequently, high-protein and low-glycemic/low-carb diets are becoming more and more popular. Both effectively increase satiety and may improve fat burning by reducing insulin demand. With that said, this article examines the latest scientific findings on nutrition and fat loss.
Type of Carb and Extra Lard
The recent literature review By Dr. Judith Wylie-Rosett and colleagues at the Albert Einstein College of Medicine pointed out that the increase in fructose (fruit sugar) consumption has paralleled an increased prevalence of obesity in the U.S.1 Compared with glucose, fructose ingestion favors de novo lipogenesis, which could increase body fatness. Furthermore, animal studies have shown a relationship between fructose intake and insulin resistance (obesity is positively correlated to insulin sensitivity). Finally, a recent study has shown that ingestion of high-fructose beverages with meals resulted in elevated triacylglycerols (harmful blood lipids).
High-fructose corn syrup is used extensively in processed foods, including supposedly “heart healthy” low-fat products. Unless you want to look like a Michelin Man, it’s certainly a good idea to minimize the intake of syrup-containing products such as baked goods, soft drinks and condiments. However, there’s no reason to avoid fresh fruits.
Dr. Wylie-Rossett and co-workers also noted that several single-meal studies have shown that glycemic index is directly related to postprandial (after dinner) hunger and food intake. However, glycemic index can be somewhat misleading. For example, a carrot has a high glycemic index, but because it contains relatively little carbohydrate, it
ends up with a modest glycemic load. Thus, it’s better to follow glycemic load rather than glycemic index. Simply stated, increase consumption of vegetables, legumes and fruits, and decrease intake of sugars, refined grains and potatoes.
Very-Low-Carb Diets and Blood Lipids
Well-controlled studies that have examined body composition after very-low-carb diets have reported enhanced fat loss and preservation of muscle mass, but some have claimed very-low-carb diets may have adverse effects on blood lipids. However, there is little, if any, evidence supporting this contention. A recent state-of-the-art literature review by Drs. Jeff Volek and Matthew Sharman at the University of Connecticut provided the following take-home messages:2
1. Short-term very-low-carb diets are associated with improvements in a number of heart disease risk factors.
2. The most consistent effect is a remarkable decrease in triacylglycerols, and this response is not explained by changes in bodyweight.
3. Compared with the low-fat diet, the very-low-carb diet results in a significant increase in good cholesterol (HDL).
4. Very-low-carb diets may also increase bad cholesterol (LDL). However, Dr. Volek and colleagues observed that there was a significant increase in LDL particle size. Smaller LDL particles are associated with higher risk for heart disease, so shift in LDL particle size is an important finding.
High Calcium Intake Increases Fecal Fat Excretion
There’s evidence suggesting the intake of calcium may play an important role in bodyweight regulation. So, Dr. R. Jacobsen and co-workers at the Royal Veterinary and Agricultural University examined whether high and low calcium intakes in diets either high or normal in protein content have effects on metabolic rate, substrate burning and fecal fat excretion.3 Results indicated that calcium has no effect on metabolic rate or fat burning. However, fecal fat excretions increased about 2.5-fold during high-calcium/normal-protein diet compared with the low-calcium/normal-protein and the high-calcium/high-protein diets. An increase of 1,000 milligrams in calcium intake resulted in an increase of 5.4 grams in fat excretion. So, if you want to shred extra lard, make sure you take in enough calcium.
Low-Carb Diets and Diabetics
In 2001, the American Heart Association’s Nutrition Committee suggested, without any evidence, that high-protein/low-carb diets are especially risky for diabetics. However, recent well-controlled studies show that low-carb diets may be especially beneficial for diabetics. For example, Dr. Yoh Miyashita and colleagues at the Toho University in Japan investigated the effects of a low-carb diet on glucose and lipid metabolism in type 2 diabetic patients with extra lard.4 The authors concluded, “Low carbohydrate content in the low-calorie diet showed more favorable effects
on reducing visceral fat, lower serum insulin levels and improving serum lipid levels compared to an isocaloric high- carbohydrate diet.”
The American Diabetes Association (ADA) still recommends that carb-intolerant diabetics eat more carbs. This weird recommendation may have something to do with the fact that numerous drug companies and manufacturers of “heart-healthy” low-fat carb-rich foods (Archway Cookies, Coolbrands International, Murray Sugar Free Cookies, General Mills, Voortman Cookies, etc.) can also be found on its sponsor sheet. Clearly, high-carb diets dramatically increase use of diabetic drugs, so drug companies are more than happy to support ADA.
Poor JAMA Diet Study
The purpose of the recent JAMA study was to assess adherence rates and effectiveness of four diets: Atkins, Zone, Weight Watchers and Ornish.5 The conclusion was that “Each popular diet modestly reduced bodyweight and several [heart disease] risk factors at one year.” It should be noted, however, that after two months of “maximum effort,” participants selected their own levels of dietary adherence. For example, Atkins dieters followed a low-carbohydrate diet only during the first month, when the mean carbohydrate intake was 68 grams. By months six and 12, carbohydrate intake was a whopping 190 grams. This is clearly not a low-carb diet. In my view, this was a pretty worthless study. Do we really need more taxpayer-funded “studies” telling us all diets are hard to stick to?
High-Protein Diet Increases Expression of UCPs
Uncoupling proteins (UCPs) decrease efficiency of energy metabolism and thus, more energy will be wasted as heat. Dr. Klaus Petzke and collegues at the German Institute of Human Nutrition hypothesized that a high-protein diet leads to an activation of UCP expressions, which in turn contributes to lower metabolic efficiency and an increase in fat burning.6 Adult rats were adapted to diets containing either 13.8%, 25.7%, or 51.3 % protein. The results indicated that the intake level of protein is associated with UCP expression in liver and skeletal muscle. In other words, a high-protein diet decreases metabolic efficiency and helps burn fat.
Metabolic Advantage of Low-Carb Diets
A recent literature review by this author examined the science behind the metabolic advantage of low-carb weight loss diets.7 The conclusion was that “different diets lead to different biochemical pathways that are not equivalent when correctly compared through the laws of thermodynamics. It is inappropriate to assume that the only thing that counts in terms of food consumption and energy balance is the intake of dietary calories and weight storage. Well-controlled studies suggest that calorie content may not be as predictive of fat loss as is reduced carbohydrate consumption. Biologically speaking, a calorie is certainly not a calorie.” Free full text paper is available at http://www.sportsnutritionsociety.org/site/admin/pdf/Manninen-JISSN-1-2-21-26-05.pdf.
Metabolic Urban Legends
Another recent paper by his author refuted numerous metabolic urban legends related to low-carb intake.8 The key take-home messages were as follows:
1. A low-carb diet is, if anything, protective against muscle loss during energy restriction.
2. There is no actual requirement for dietary carbs for humans.
3. Dietary ketosis is a harmless physiological state.
Got it? Good. Free full text paper is available at http://www.sportsnutritionsociety.org/site/admin/pdf/Manninen-JISSN-1-2-7-11-04.pdf
Green Tea Boosts Endurance, Fat Burning
Dr. Takakoshi Murase and coworkers at Kao Corporation in Japan investigated the effects of green tea extract on endurance capacity, energy metabolism and fat burning in mice over a 10-week period.9 Interestingly, swimming times to exhaustion for mice fed green tea were prolonged by eight to 24 percent. The effects were dose dependent and accompanied by higher rates of fat burning. The authors state,: “We have shown that [green tea] is beneficial for improving endurance capacity and that this effect is accompanied by a stimulation of lipid [fat] metabolism. Although the clinical efficacy of [green tea] has not yet been confirmed in human studies, our results suggest that [green tea] may be a useful tool for improving endurance capacity. “ Whatever the case, green tea is an ultra-safe product, so you have nothing to lose (but fat) and everything to gain.
Bottom Line
Individuals who follow a high-carbohydrate/low-fat diet may be at risk for obesity, lipid abnormalities and diabetes. As some smart guy once said, “When leading authorities are all in agreement, they are almost always wrong.”
