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 to 12 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.Fiber Safety
Chromium Enhances Insulin's Actions
- Take fiber supplements with a full 8-ounce glass of water.
- Drink eight 8-ounce glasses of water daily while taking fiber.
Chromium is an essential trace element required for normal carbohydrate metabolism. Chromium increases insulin binding, the number of insulin binding receptors, and insulin sensitivity (Anderson 1997; Vincent 2000).
Human studies show that chromium picolinate decreases insulin levels and improves glucose disposal in obese and type 2 diabetics ( Anderson et al 1997; Bahadori et al 1999; Ghosh et al 2002). Chromium picolinate was evaluated for treatment of insulin resistance syndrome in obese rats. Oral chromium picolinate improved carbohydrate and lipid metabolism and enhanced skeletal muscle glucose transport in the obese rats (Cefalu et al 2002). In infant rats, elevated doses of chromium picolinate increased muscle mass by stimulating protein anabolism (muscle building) (Bernao et al 2004). In growing pigs, plasma glucose concentrations in chromium-supplemented pigs were lower before feeding, suggesting increased insulin sensitivity (Van de Ligt et al 2002).
Chromium polynicotinate (600 mcg daily for two months) given to modestly dieting and exercising African-American women caused a significant loss of fat and sparing of muscle compared with placebo (Crawford et al 1999). A formula including chromium polynicotinate reduced appetite, inhibited fat synthesis, and decreased body weight in 60 moderately obese subjects in an eight-week randomized, double-blind, placebo-controlled trial (Preuss et al 2004). Another double blind, four-week trial with a formula including chromium increased the rate of body fat loss and helped to maintain muscle mass (Hoeger et al 1998).
Always take antioxidants when taking chromium to protect against any oxidative reactions that might occur in response to chromium (Hendler et al 2001).Physical Activity
One of the most modifiable of risk factors for obesity is physical inactivity (Grundy et al 1999). In unveiling new health objectives, the US government dramatically increased target exercise goals. To maintain a healthy weight, the NIH now recommends that adults engage in 30 to 60 minutes of exercise most days of the week. For weight loss, or for people who have recently lost weight and want to keep it off, the recommendation is between 60 and 90 minutes of exercise most days of the week (MMWR 2002). Consult your physician before embarking on any exercise program.Magnesium Is as Important as Chromium
Although chromium has received considerable media attention, scientific literature shows that magnesium has a more important role in regulating carbohydrate metabolism. Magnesium is involved in a number of reactions required for cells to uptake and metabolize glucose. Magnesium deficiency causes insulin resistance and elevated blood sugar levels (Paolisso et al 1990; Nadler et al 1993; Nadler et al 1995; Lefebvre et al 1994).
Approximately 68 percent of Americans are magnesium deficient. When magnesium-deficient individuals undertake a diet, they often become severely magnesium deficient, which aggravates insulin resistance and contributes to failure of the diet.
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