Intermittent Fasting Diet for Bodybuilding and Weight Loss

The intermittent fasting approach to diet may go against everything you’ve heard about food, metabolism and muscle. But the research (not to mention the experience of many practitioners—including yours truly) has led me to believe this is one of the most effective dietary strategies you can utilize.

You may have grown up reading about the importance of small, frequent meals for “firing up your metabolism.” This was the bodybuilding dogma for decades and I also used to believe it.

But research has not demonstrated any metabolic difference in small, frequent meals versus large infrequent eating. One study, for example, compared the metabolic affect of two meals a day with eating seven meals a day in thirteen subjects. Researchers concluded there were “no consequences for the total 24 h energy expenditure (24 h EE) of the two feeding patterns.”1

Having said this, I’ll tell you two distinct advantages to an intermittent fasting approach to diet:

1. Simplicity/Compliance

Small, frequent meals are fine if this way of eating helps you consistently hit your daily caloric goals. But eating 6-7 times a day may not be practical for those of us who don’t make a living in the fitness profession.

I’ve also found low carbohydrate approaches to be very effective. But compliance is also an issue here—going several days without carbs is just kind of a pain in the rear end (memories of “keto breath” come to mind).

This is the beauty of intermittent fasting. It does take some getting used to, but you don’t have to stress over eating every few hours or completely abstaining from one type of food. This is important, because long-term compliance will be the most important factor in whether or not a diet “works.”

For me the adjustment to the diet kind of works in reverse to other things I’ve tried. In other words, it gets easier to do over time. It seems going for short periods of time without eating re-wires the brain and reduces compulsive eating. That’s been my experience, and many other practitioners attest to the same.

2. Hormonal

Some fear a short fast will slow the metabolism or put the body in “starvation mode.” But this doesn’t seem to be the case, either. A short fasting period will, in fact, maximize your fat burning potential. There are positive effects on growth hormone and catecholamines, both of which aid in fat loss.

Going longer periods without eating also causes the body to burn fat (vs. carbohydrates) for fuel. The study I cited earlier noted that subjects experienced increased fat oxidization when eating only two meals a day.

Some fear going without food will cause muscle loss, but this doesn’t seem to be the case. The bottom line is this: you will not lose muscle mass while dieting if you lift weights.

Two Basic Approaches:

You’ll basically see two main strategies of intermittent fasting practiced by those who are wanting to lose fat or stay lean.  I’ll explain them briefly here, but you can click the links for more information on helpful resources.

The 16/8 approach refers to fasting for 16 hours, then eating for 8.  In other words, you’d skip breakfast and lunch, consuming your calories in the afternoon/evening.

Some plans call for a 24 hour fast once or twice a week (about every five days). Brad Pilon’s Eat-Stop-Eat is a very well researched book for those who want this simplified approach to intermittent fasting.  Going 24 hours with no food may sound impossible, but the nice thing is you don’t have to go a whole day without a meal.  In other words, you could have dinner one night then not eat until dinner the next night.  It doesn’t mean you can eat everything in sight the rest of the time, but Pilon explains that in more detail in his book.

Which one of these is right for you?  It really just depends on you.  I prefer the structure of the 16/8 approach.  But you may prefer the flexibility that comes with fasting only once every five days.  The bottom line is either will work as long as you consistently apply the principles and keep a negative calorie balance long enough to lose fat.

Let me add one thing here: I don’t think intermittent fasting is the best for a beginner trainee trying to put on the first 15-20 lb. of muscle (especially if said trainee is in his teens or early twenties).

Reference:

1. Eur J Clin Nutr. 1991 Mar;45(3):161-9. Influence of the feeding frequency on nutrient utilization in man: consequences for energy metabolism.

Women Weight Training: why girls should lift weights.

I always recommend weight training to women who are interested in improving their overall health and appearance. This includes women who want to lose weight. I’ll give you three reasons women should try resistance training:

1. Weight Management and Health: resistance training is a great calorie burner. Train for about three days a week and you should have a much easier time achieving a negative calories balance (if fat loss is your goal).  It also improves your overall health, including cardiovascular health.

One study found that following a simple weight lifting routine helped middle-aged women manage their weight.

PURPOSE: The aim of this study was to examine the association of exercise frequency (ExFreq) and volume (total weight lifted by military press and squats (SQ)) with change in body composition among postmenopausal women participating in a progressive resistance training study.

METHODS: Previously, sedentary women (n = 122, age = 56.3 +/- 4.3 yr) were followed for 6 yr. At 6 yr, there were women who had been randomly assigned to resistance training at baseline (n = 65) controls that were permitted to cross over to the exercise program at 1 yr (n = 32) and 25 true controls. Exercisers and crossovers directed to perform eight core exercises for two sets of eight repetitions at 70%-80% of one-repetition maximum, three times weekly, plus progressive weight bearing, stretching, and balance. Body weight and fat were measured at baseline and annually using anthropometry and dual-energy x-ray absorptiometry.

RESULTS: Average change in body weight and total body fat were 0.83 +/- 5.39 and 0.64 +/- 4.95 kg at 6 yr, respectively. In multiple linear regression, ExFreq, military press, and SQ were significantly inversely associated with change in body weight (standardized beta coefficient (SBC) = -0.22 to -0.28, P < 0.01), fat (SBC = -0.25 to -0.33, P < 0.01), and trunk fat (SBC = -0.20 to -0.31, P < 0.03) after adjusting for age, years on hormone therapy, change in lean soft tissue, baseline body composition, and baseline habitual exercise. The lowest tertile of SQ (equivalent to 2.5% attendance) demonstrated significant gain in weight, fat, and trunk fat over 6 yr (P < 0.004), whereas the highest tertile SQ (equivalent to 64% attendance) was able to maintain their weight, total, and regional fat.

CONCLUSIONS: We conclude that resistance training is a viable long-term method to prevent weight gain and deleterious changes in body composition in postmenopausal women.1

Another study found a simple, home-based routine improved the cardiovascular health of premenopausal women:

The present study investigates the effect of home-based resistance training on arterial stiffness in healthy premenopausal women. Twelve healthy non-smoking and normotensive women who were not actively involved in regular physical exercise (aged 42-55 years) performed home-based resistance training twice weekly for 10 weeks using body weight and light dumbbells. Each training session required approximately 40 min to complete. Arterial stiffness was measured using brachial-ankle pulse wave velocity (baPWV). We also determined serum total cholesterol, HDL cholesterol, glucose, triglyceride, insulin, and adiponectin and calculated the homeostasis model assessment of insulin resistance (HOMA-IR), an index of insulin resistance. After home-based resistance training, baPWV, total cholesterol, LDL cholesterol, insulin, and the HOMA-IR decreased, whereas adiponectin increased (P < 0.05) and levels of HDL cholesterol, glucose, triglyceride, blood pressure, and heart rate remained unaffected. These results suggest that home-based resistance training benefits vascular function in healthy premenopausal women.2

2. Hormonal Advantages: I ran across some interesting research that was done with middle-aged women. One group did only aerobics while another did aerobics and resistance training:

BACKGROUND: The purpose of this study was to examine the effects of combined exercise training on growth hormone (GH), insulin-like growth factor-1 (IGF-1), and metabolic-syndrome factors and determine whether the changes in GH and/or IGF-1 induced by exercise correlate to the metabolic-syndrome factors in healthy middle-aged women (50-65 years of age).

METHODS: The participants were randomly assigned into an aerobic-exercise training (walking + aerobics) group (AEG; n = 7), a combined-exercise training (walking + resistance training) group (CEG; n = 8), or a control group (CG; n = 7). Exercise sessions were performed 3 times per wk for 12 wk. The aerobic-exercise training consisted of walking and aerobics at 60-80% of heart-rate reserve, and the combined-exercise training consisted of walking and resistance exercise at 50-70% of 1-repetition maximum.

RESULTS: GH, percentage body fat, fasting glucose, systolic blood pressure, and waist circumference were significantly improved in CEG (p < .05). However, GH induced by exercise training showed no correlation with metabolic-syndrome factors. IGF-1 was not significantly increased in either AEG or CEG compared with CG.

CONCLUSION: These results indicate that the combined-exercise training produced more enhancement of GH, body composition, and metabolic-syndrome factors than did aerobic-exercise training.3

3: Osteoporosis Prevention: We know astronauts living in zero gravity environments lose bone mass. Those confined to bed rest also tend have some bone loss. In other words, there seems to be a direct connection between bone health and the resistance applied to bones. Weight training seems to help maintain or increase bone density. The best strategy would be to start while you are young and continue the habit. Here is just one of many studies you can find:

The increase in lifespan and in the proportion of elderly women has increased the focus on menopause induced physiological alterations. These modifications are associated with the elevated risk of several pathologies such as cardiovascular disease, diabetes, obesity, hypertension, dyslipidemia, non-alcoholic fat liver disease, among others. Because of estrogen levels decline, many tissue and organs (muscular, bone, adipose tissue and liver) are affected. Additionally, body composition suffers important modifications. In this sense, there is a growing body of concern in understanding the physiological mechanisms involved and establishing strategies to prevent and reverse the effects of menopause. The hormone reposition therapy, diet and physical exercise have been recommended. Among the diverse exercise modalities, resistance training is not commonly used as a therapeutic intervention in the treatment of menopause. Thus, the aim of this review was to analyze the physiological alterations on several organs and systems induced by menopause and ovariectomy (experimental model to reproduce menopause), as well as, to study the effects of resistance training in preventing and reverting these modifications. In conclusion, resistance training promotes beneficial effects on several organs and systems, mainly, on muscular, bone and adipose tissue, allowing for a better quality of life in this population.4

Take note here—the study concluded resistance training could improve one’s “quality of life.”

More Thoughts:

I know what some of you are thinking: “I don’t want to get all big and bulky.” Don’t worry—women simply don’t have the same hormonal makeup as men, so there’s no need to fear turning into the she-hulk.  Lifting weights will, in fact, give you muscles in all the

right places.  Don’t believe me?  Just check out pictures/websites of female fitness models.  All of them do some kind of resistance training as part of their overall strategy.

Remember, you don’t even have to join a gym to get started with this:  you can train at home using your own body weight and/or some simple equipment.

 

References:

1. Med Sci Sports Exerc. 2010 Jul;42(7):1286-95.

2. Eur J Appl Physiol. 2009 Sep;107(1):113-7. Epub 2009 Jun 14.

3. Int J Sport Nutr Exerc Metab. 2010 Feb;20(1):21-6.

4. Int J Sports Med. 2010 Nov;31(11):761-7. Epub 2010 Nov 5