Obesity
Strategies to Fight a Rising Epidemic
Updated: 01/19/2006

There may be more myths and misunderstandings about obesity than about any other major health epidemic. Americans are constantly besieged with faulty or incomplete weight-loss information—some of it from mainstream sources. To lose weight, we are advised to avoid entire food categories (such as carbohydrates or fats) or to eat only one food category (proteins, for instance). And every new fad diet is accompanied by an avalanche of new products and marketing hype as companies try to cash in on Americans' desperate desire to slim down. The result is a stream of conflicting information that leaves many people confused.

Worse yet, none of it seems to be working. The National Institutes of Health (NIH) estimate that more than half the adult population of the United States is overweight (defined as a body mass index [BMI] of 25 to 30). A significant number of these people are obese (defined as a BMI greater than 30). The obesity epidemic is even beginning to affect children, whose obesity rates have doubled in the past two decades (NIH 2005). And instead of declining, obesity rates are rising, along with the frequency of conditions that are closely associated with obesity, such as type 2 diabetes and metabolic syndrome.

The government's answer to the growing epidemic of obesity has been to recommend more exercise and a balanced diet. While there is no doubt these strategies are important, they also display an incomplete understanding of the biological and hormonal changes that underlie obesity among aging adults. The fact is that as we age, we undergo physiological changes that encourage weight gain. These include hormonal changes and alterations in the way our bodies process nutrients.

Life Extension (LE) believes that, in addition to a sensible, balanced diet and exercise, the only way to successfully lose weight is to address the underlying hormonal imbalances that promote weight gain. Ideally, by using bioidentical hormone replacement, dieters can restore their hormonal profile to what it was at the age of 25, an age at which weight gain is less often a problem. In addition, numerous dietary nutrients have been shown to encourage weight loss. In this chapter, LE presents a specific plan, based on scientific literature that will help aging people lose weight.

Why Middle-Aged Men Gain Weight

About age 30 to 35, most men (and some women) notice they are gaining weight around the middle. Their pants become tight and at some point no longer fit. The words “pot belly,” “beer belly,” or “spare tire” are sometimes used to describe the medical condition called “abdominal obesity.” This sort of fat accumulation greatly increases the risk of cardiovascular and other diseases.

Low testosterone = abdominal fat gain

As it turns out, there is a scientific explanation for the tendency toward abdominal obesity among middle-aged men. As men age, their levels of free testosterone decline, and levels of estrogen and insulin increase. This is partly because aging men convert much of their testosterone into estradiol, a form of estrogen. Of the remaining testosterone, much is bound to sex hormone–binding globulin, a protein in the blood, and is not biologically active. Studies have shown that men with low free testosterone have higher rates of coronary artery disease, mental depression, and dementia (Tan et al 2004).

The idea behind testosterone replacement therapy is to restore the level of free testosterone to that of a healthy 25-year-old to counteract the effects of increased estrogen. Studies have shown that fat cells, particularly abdominal fat cells, convert testosterone to estradiol (Schneider et al 1979; Kley et al 1980; Killinger et al 1987; Khaw et al 1992). The more belly fat a man accumulates, the greater the conversion of his testosterone into estradiol. As long as free testosterone is low and the ratio of estrogen to insulin is high, most aging men will store fat around their belly (Abate 2002).

Clinical studies have shown that testosterone replacement therapy can provide a variety of benefits.

• In one study of 86 men aged 50 to 70, waist-to-hip ratio and blood pressure markedly decreased after 60 days of testosterone therapy (Li et al 2002).
• Another testosterone-replacement study in middle-aged obese men showed improved waist-to-hip ratio along with a decrease in plasma insulin and an increase in glucose disposal, suggesting improved insulin sensitivity (Marin et al 1992).
• In another trial, abdominally obese middle-aged men showed improved glucose control, decreased abdominal body fat, and improved sexual function after testosterone therapy (Boyanov et al 2003).

Given that these studies looked only at testosterone levels, one can only speculate about what the results might have looked like if excess estrogen and insulin had also been suppressed.

Hormone Therapy for Women

In women, the relationship between excess body fat, testosterone, estrogens, and progesterone is somewhat more complicated.

It is believed that estrogen reduces lipid oxidation at puberty and in early pregnancy to facilitate efficient fat storage in preparation for fertility, birth and lactation (O'Sullivan et al 2001; Rosenbaum et al 1999). This modification in lipid oxidation enables fat storage without significant changes in dietary fat and caloric intake (O'Sullivan et al 2001).

The drop in gonadal estrogen production at menopause is associated with an increase in the waist to hip ratio and an increase in size of visceral adipose tissue, and administration of estrogen to postmenopausal women is associated with a lowering of the waist to hip ratio (Rosenbaum et al 1999). However, as women age, levels of progesterone and all estrogens (including estriol, estradiol, and estrone) decline..Progesterone declines much more rapidly than do the estrogens, leading to “estrogen dominance” (Lee et al 1999) . LE believes the imbalance of estrogens and progesterone may play a pivotal role in the dynamics of metabolic obesity and visceral fat accumulation in aging women.

DHEA and Weight Loss

Testosterone and estrogen are not the only hormones implicated in weight gain. Low levels of DHEA (dehydroepiandrosterone), a steroid hormone, have also been linked to increased weight gain. Virtually everyone over age 35 experiences a significant reduction in DHEA. Studies suggest that supplementing with DHEA produces beneficial body composition changes (Villareal et al 2000; Villareal et al 2004).

For example, a 6-month trial in aging men and women with low DHEA levels demonstrated that 50 mg of DHEA per day reversed age-related changes in fat mass (Villareal et al 2000).

Another study showed that DHEA decreased abdominal obesity and improved insulin action. This randomized, double-blind, placebo-controlled trial evaluated 50 mg of DHEA per day for 6 months in 56 individuals with age-related decline in DHEA levels. The study showed that DHEA was associated with significant decreases in visceral and subcutaneous fat and improved insulin sensitivity (Villareal et al 2004).

Note: In woman DHEA can convert to testosterone, which is acceptable as long as testosterone is kept within proper range.

7-keto DHEA. A metabolite of DHEA called 7-keto DHEA has also attracted considerable attention for its value as a fat-loss supplement. Like DHEA, 7-keto DHEA levels dramatically decline with age (Marenich 1979).

In animal studies, 7-keto DHEA boosted fat-burning enzymes (Bobyleva et al 1993; Bobyleva et al 1997). Studies using 7-keto DHEA supplements produced encouraging results. For example, researchers assessed the effects of taking 100 mg of 7-keto DHEA or placebo twice daily for 60 days. Compared with placebo, the 7-keto group lost more body weight (6.3 lb vs. 2.1 lb). This study also found that supplementing with 7-keto DHEA was associated with a significantly greater percentage of body fat loss compared with the placebo group (Kalman et al 2000).

Because of the fat burning, or thermogenic effects of 7-keto DHEA, simultaneous supplementation with antioxidants is recommended to help guard against excessive free radical production. Animal studies have shown that 7-keto DHEA is not converted into testosterone or estradiol (Lardy et al 1995). Unlike caffeine or ephedra, 7-keto DHEA does not have a noradrenaline-induced central nervous system stimulating effect, nor does 7-keto increase heart rate or blood pressure.

The Thyroid Connection

There has been a great deal of misunderstanding about the connection between thyroid hormone and weight loss. Produced in the thyroid gland, thyroid hormone is the master metabolic control mechanism. A lack of thyroid hormone (a condition called hypothyroidism) is connected to weight gain, as well as dry hair and skin, fatigue, and sluggishness. Overweight people may want to check their thyroid levels to make sure they aren't lacking thyroid hormone. If they are, a physician may prescribe thyroid hormones to correct the condition.

In the 1960s and 1970s, the connection between hypothyroidism and weight gain caused some people to assume they could speed up their metabolism and lose weight by using supplemental thyroid hormones. This led to an abuse of thyroid hormone as people created an artificial state of excess thyroid hormone (a condition medically known as hyperthyroidism). Hyperthyroidism can cause weight loss as well as irregular heartbeats, sweating, and tremors. Although people taking supplemental thyroid hormones may have lost weight, they were losing lean muscle mass in addition to undesirable body fat (Braunwald et al 2001).

Today our understanding of the relationship between thyroid hormone and weight loss is more complete. It works like this: when calorie intake is drastically reduced, the activity of an enzyme called 5'-monodeiodinase is reduced; 5'-monodeiodinase is necessary to convert the thyroid hormone T4 into T3. As a result, the levels of T3 drop (Merimee et al 1976; Carlson et al 1977; Beer et al 1989; Wadden et al 1990). T3 is the stronger form of thyroid hormone. The connection is especially valid when it comes to a reduction in carbohydrate calories:

• As little as 50 g of glucose reverses the change in T3 (Burman et al 1979)
• Replacement of carbohydrate with fat results in thyroid hormone changes typically observed during times of starvation (Danforth et al 1975; Azizi 1978)
• P rotein consumption improves the rate of T3 generation more than carbohydrate consumption (Harris et al 1978)

Therefore, consuming more carbohydrate calories during dieting can counteract the drop in T3 associated with dieting. Alternatively, decreased T3 levels can be directly replaced. Some older clinical studies testing this theory were promising. However, later studies showed that direct T3 supplementation by dieters was connected with muscle wasting (Gardner et al 1979; Vignati et al 1978). During fasting, administration of large doses of T3 caused even more severe muscle wasting (Carter et al 1975).

More recent studies suggest that using very low doses of replacement thyroid hormone during dieting, once the body has switched over from carbohydrate burning to fat burning, may not be associated with muscle breakdown (Nair et al 1989; Byerley et al 1996, Pasquali et al 1984).

The Insulin Trap

Recent advances in dietary science have highlighted the crucial role of insulin in weight gain. Produced in the pancreas, insulin is a critical hormone for the control of blood sugar (glucose). Its job is to transport glucose into cells, where the glucose is burned as fuel. While this process is necessary for life, abnormalities in the insulin-glucose system caused by aging, lack of exercise and poor diet can cause major health problems. In aging, cells become more resistant to the effects of insulin. As cells become increasingly insulin resistant, the body compensates by increasing the number of insulin receptors on cells and secreting more insulin in an attempt to drive more blood sugar into muscle and liver cells (Fulop 2003).

Insulin resistance is a dangerous condition. Research suggests that adipose tissue (fat) is a source of pro-inflammatory chemicals that have a role in the development of insulin resistance (Sharma AM et al 2005). Insulin resistance is associated with obesity (in particular, abdominal obesity) (Greenfield JR et al. 2004). It is also associated with aging muscle (Nair KS 2005), physical inactivity, and genetics.

This increase in insulin (called hyperinsulinemia) and decreased insulin sensitivity have a number of harmful effects, including contributing to diseases associated with being overweight (Zeman et al 2005; Garveyet al 1998)

Over time, high insulin and insulin resistance may lead to type 2 diabetes in susceptible individuals, a major risk factor for heart disease. A study sponsored by the NIH showed that over a 10-year period, hyperinsulinemia was associated with increased all-cause and cardiovascular mortality, independent of other risk factors (NIH 1985).

Controlling insulin levels as we age is essential for overall health, longevity, and weight management. An increasing number of physicians recognize the role of insulin resistance in the current obesity epidemic. The good news is that nonprescription drugs and low-cost dietary supplements that have demonstrated beneficial effects upon insulin action are already available.

Fiber Reduces Insulin Spike

When it comes to weight loss, fiber has not received the attention it deserves. The recent focus on carbohydrates has led some people to reduce their intake of whole fruits and some vegetables because these foods contain carbohydrates. By doing this, those dieters deprive themselves of the many benefits of a naturally fiber-rich food source. According to the American Heart Association (AHA) and the National Cancer Institute (NCI), Americans should consume about 30 g or more of fiber every day. The actual average consumption, however, is between 12 and 17 g (AHA 2005; NCI 2005).

Consumed before a meal, soluble fiber has multiple benefits. First, it is filling and causes people to eat less because they are satiated sooner. Anecdotally, LE has received reports that some people can actually cut the size of their meals in half by consuming a glass of soluble fiber mix before eating.

Equally important, consuming fiber before meals can reduce the rapid absorption of simple carbohydrates (such as refined sugar) and modulate blood sugar levels (Anderson et al 1993). A review of clinical studies of fiber shows that it has numerous weight-loss benefits, including the following:

• Soluble fiber-rich bread improved glycemic control, reduced blood pressure, and decreased cholesterol and triglyceride levels (Nizami et al 2004).
• Consumption of an additional 14 g of fiber per day for more than two days was associated with a 10 percent decrease in calorie intake and body weight loss of 1.9 kgover 3.8 months (Howarth et al 2001).
• A prospective cohort study showed that weight gain is slowed with higher intake of high-fiber, whole-grain foods, whereas study subjects put on more weight when consuming refined-grain foods (Liu et al 2003).
• A prospective, randomized, double-blind study showed that soluble fiber supplements can increase post-meal satisfaction (satiety) significantly (Heini et al 1998).
• A randomized controlled clinical trial demonstrated that soluble fiber can lower lipids and plasma glucose levels (Aller et al 2004).
• A clinical trial suggested that a diet rich in fiber may lower blood pressure moderately (He et al 2004).
• A highly regarded study in the New England Journal of Medicine showed that a high-fiber diet (50 g fiber, including 25 g soluble and 25 g insoluble) lowered 24-hour plasma glucose and insulin concentrations (Chandalia et al 2000).

Soluble fiber is found in oat bran, barley, vegetables, fruits, and other foods. However, for weight-management purposes, it is important to have soluble fiber before every meal. Therefore, soluble fiber supplements (such as powders or capsules) should be kept where meals are consumed, such as the kitchen or the office.

Some people shy away from fiber because they experience lower bowel disturbances if too much fiber is consumed at first. This can be avoided by beginning with a low dose of fiber before each meal and gradually increasing doses over a two- to three-week period. Once the body adjusts to increased fiber intake, gastrointestinal side effects usually disappear.

How to Use Fiber Supplements

Before every meal, consume enough soluble fiber to slow the rapid carbohydrate absorption that can cause insulin levels to spike. Consuming soluble fiber before each meal also enables you to feel satisfied sooner, thereby reducing the number of calories consumed.

The type of dietary fiber to use is an important consideration. To help induce weight loss, purified soluble dietary fibers, such as pectin, guar, psyllium, glucomannan, alginate, and beta-glucan, help normalize blood glucose and have an antidiabetic effect (Trepel 2004). A study showed that 7 g of soluble fiber (psyllium) significantly decreased hunger feelings, decreased food intake, and blunted increases in serum glucose-insulin levels (Rigaud et al 1998). A trial in patients with type 1 diabetes illustrated that 16 g of soluble fiber (guar) daily significantly decreased blood glucose after eating (Lafrance et al 1998). Another study showed that as few as 5 g of soluble fiber (alginate) significantly decreased the post-meal rise in glucose and insulin (Torsdottir et al 1991).

Some people find it difficult to consume high-dose fiber powder drinks before every meal. Yet taking only a few grams of specialized soluble fiber blends can produce remarkable benefits. Led by University of Toronto scientist Vladimir Vuksan, Ph.D., researchers combined glucomannan with two other soluble fibers (xanthan and alginate) in an exact ratio and added mulberry concentrate (20:1) to enhance glycemic-control and lipid-lowering effects (Andallu et al 2001). This proprietary blend is called PGX.

At the 2004 meeting of the American Diabetes Association (Orlando, Florida), results of two studies using PGX fiber blend were presented by researchers from the Risk Factor Modification Centre at St. Michael's Hospital and the University of Toronto (Vuksan et al 2004):

• Study participants who took 3 g of the fiber blend had a 65 percent reduction in post-meal glucose elevation after consuming a 50-gram acute glucose challenge.
• Study participants who took 3 g of the fiber blend (three times a day, before meals) had a 23 percent reduction in post-meal glucose, a 40 percent reduction in post-meal insulin release, and a 55.9 percent improvement in whole-body insulin sensitivity scores.
• Study participants taking the fiber blend reduced body fat by 2.8 percent from baseline by the end of the three-week study period.

Optimal weight-loss benefits occurred when six PGX capsules were taken before meals, although some studies indicate as few as two capsules might produce some results (Vuksan et al 2004).

An advantage of PGX is that its benefits may be obtained by swallowing capsules, which usually do not cause intestinal distress. However, to induce early satiety, drinking a soluble powder mix before meals is preferable to swallowing capsules.

The typical dose for soluble fiber drink mix is 8 to12 g taken before meals. Begin with only 4 g before each meal for the first week or two to allow your digestive system to adjust to higher fiber intake.