Dieting plus exercise increased fat loss
Dieting plus aerobic exercise increases fat loss more than dieting alone. This was the conclusion of a recent study of obese women. Fat
loss in the diet plus exercise group averaged 17.2 lbs. compared to only 12.1 lbs. in the diet-only group. The extra fat loss was due to
increased utilization of fat during exercise. Both groups lost a similar amount of lean body mass (2.9 lbs vs. 3.5 lbs, respectively).
Formerly-obese burn less fat
Formerly obese individuals burn less fat during normal daily activities than their never-obese peers according to a recent study. This
helps to explain why exercise is crucial for maintaining weight loss in formerly-obese individuals.
Diet + lifting + aerobics maximizes fat loss
A moderately-reduced calorie diet (a low fat diet of approximately 1,240 calories per day) plus weightlifting and aerobic cycling maximized
fat loss without causing a loss of muscle. In this study a group of overweight women were assigned to one of five groups: I) control; 2)
diet-only; 3) diet + cycling; 4) diet + weightlifting; 5) diet + weight- lifting + cycling. Reductions in percent body fat were as follows,
respectively: 0%, 2.4%, 4,1%, 3.7%, 4.6%. No group lost a significant amount of muscle. There are two lessons to be learned from this study.
First, moderately reduce calories (to no less than 1200 calories per day) to avoid losing muscle. Second, lift weights and engage in aerobic
exercise to maximize your fat loss.
Lose weight slowly to lose fat, not muscle
A second study confirms that losing no more than 1.5 lbs. per week combined with weight lifting is the best way to lose fat not muscle.
Fourteen obese women reduced their calorie intake (and fat intake) by approximately 1,000 calories per day and lifted weights three times per
week (8 exercises, 8-12 reps). After four months the women had lost an average of 21.6 lbs. of fat and only 0.7 lbs. of muscle. A previous
study which combined diet (800 calories) and weight-training resulted in faster weight loss (2.6 lbs. per week), but also caused a significant
amount of muscle loss (24.9 lbs. of fat 8.3 lbs. of muscle). As concluded from the summary above ± you can maximize your fat loss and minimize
your muscle loss by losing no more than 1.5 lbs. per week.
Waist-to-height ratio predicts heart disease
A new study suggests that a useful way of determining a man's risk of coronary heart disease may be his waist-to-height ratio. This is because
belly fat increases the risk of heart disease more than fat on the hips and thighs. The risk of heart disease increases with waist-to-height ratio
as follows: a ratio of 0.42 increases the risk 0%; 0.44 = 30%; 0.46 = 50%; 0.48 = 70%; 0.5 = 90%; 0.52 = 120%: 054 = 130%;0.56= 180%;0.58= 190%:
greater than 0.6 = 240%. Wrist-to-height ratio is calculated by dividing wrist measurement by height, both measured in inches. For example: 36-inch
waist divided by a height of 72 inches is a ratio of 36172 or 0.5.
Ephedrine stimulates beta-3 receptors
Drug companies are in late-stage development of new drugs to treat obesity called beta-3 agonists. The hope was that these new beta-3 agonists
would be able to burn off fat by stimulating a type of adrenaline receptor called a beta-3 receptor, without affecting heart rate and blood pressure.
(The effects on heart rate and blood pressure are due to stimulation beta-1 and beta-2 receptors.) Researchers recently determined that at least
42.5% of thermogenesis induced by ephedrine is due to stimulation of beta-3 receptors. It is also interesting to note that all three beta receptors
(beta-1, beta-2 and beta-3) may be involved in ephedrine-induced thermogenesis. And one of the beta-3-agonists under development called BRL-47672
is quickly metabolized in rats (and possibly humans) into a potent stimulator of beta-2 receptors. In other words, selective beta-3 agonists may
not be as selective as the name implies and may really just be mimicking die effects of ephedrine.
Lead linked to obesity
"Get the lead out" may become a new slogan for helping to prevent obesity. Researchers at Harvard found that the weight of 20 year olds was linked to
childhood lead exposure. Those with the highest lead levels had gained the most weight. Lead levels have also been associated with violent behavior,
learning disabilities and attention-deficit hyperactive disorder. Vitamin C may be helpful in reducing these deleterious effects of lead exposure.
Fish oils may increase thermogenesis & fight depression
Has your low-fat diet left you feeling blue? A deficiency of omega-3 fatty acids, especially docosahexaenoic acid (DHA) found in fish oil,
may be the cause. This was the conclusion reached in an excellent review article from the National Institute of Alcohol Abuse and Alcoholism. Of
special interest to bodybuilders is that an adequate supply of omega-3's may be necessary to maximize fat loss (via thermogenesis) and minimize muscle
This comes from the fact that depressed patients (inferring a possible deficiency) have a low output of cAMP in response to stimulation of
beta-2 adrenergic receptors. cAMP increases thermogenesis. So a decrease in cAMP means a decrease in thermogenesis. Stimulation of beta-2 receptors
also increases nitrogen retention; in other words, saves muscle.
Previous studies have shown that fish oils can increase nitrogen retention. This may be the increased cAMP response to beta-2 stimulation. The
article also notes that omega-3's may improve insulin sensitivity, and that borage oil and omega-3's can prevent the stress-induced hypertension. The article
also provides evidence that a deficiency of n-3 fatty acids may lower children's IQ., increase the risk of heart disease, increase the risk of multiple
sclerosis, as well as cause postpartum depression and the high rate of depression among alcoholics.
The relative deficiency of omega-3's has been caused by our increased intake of omega-6 fatty acids (linoleic acid) which crowd out the omega-3's. Low-fat diets
tend to be especially deficient in omega-3's. Omega-3s are found in large quantities in fish oil and flax seed oil. Fish oils contain both EPA and DHA n-3
fatty acids, while the alpha-linolenic acid (an type of omega-3's fatty acid) found in flax seed oil can be convened in the body to DHA. Fish containing high
amounts of DHA include salmon, sardines, mackerel, trout and eel. So whether you're on a low-fat diet or not, eating fish a couple times a week or taking
a fish oil supplement may improve your health and lift your spirits.