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Intermittent fasting and stubborn fat loss
How can intermittent fasting then selectively target stubborn body fat more effectively than other diets? Well, to target stubborn body fat we need to activate b2-receptors while deactivating a2-receptors. Intermittent fasting achieves this by the following mechanisms.
1. Fasting increases catecholamine levels.
2. Fasting increases abdominal subcutaneous blood flow, which means that catecholamines will have an easier time reaching those hard-to-get areas.
3. The low insulin level reached during the fast inhibits a2-receptors. A greater time spent in the low insulin state equals a greater time spent in a state where fat can be mobilized from stubborn areas. Now you're probably thinking "why not just go on a low carb diet" to keep insulin low, but keep in mind that triglycerides inhibit HSL in a similar manner as insulin.
4. My research has indicated that the ideal state of fat burning is reached after 12-18 hours of fasting. Coupled with high levels of catecholamines, increased blood flow to stubborn regions, and low insulin for a2-receptor inhibition, this time interval is the "golden age" of stubborn fat mobilization.
Let me just explain real quick what I mean by the ideal state of fat burning. Studies have examined free fatty acid (FFA) oxidation from anywhere between the overnight fasted state to three days of fasting. While FFA oxidation increases the longer time you spend in the fasted state, the contribution of fatty acids to whole body fat oxidation changes.
In short-term fasting there's a significant increase in subcutaneous FFA oxidation. That's just a fancy way of saying that you're mainly burning body fat and nothing else. For up to 14-20 hours* after a 600-calorie meal in normal-weight subjects, fat is only mobilized from body fat stores in resting individuals.
* 14-20 hours in a completely sedentary state should easily equal 12-18 hours in real life.
Past this time point, fat burning increases further. That goes without saying. But it's not necessarily the type of fat you're after that you'll be burning. Somewhere in between the 10- and 30-hour time point, the oxidation of intramuscular fat increases greatly, but no increase is seen in subcutaneous fat. Subcutaneous fat simply can't keep up with demand, so you're playing a game of diminishing returns if you push the fast too long. Coupled with the escalating rate of de novo gluconeogenesis, and subsequent risk of muscle catabolism, fasting for too long may not be very conducive for a lean individual seeking optimal lean mass retention while targeting stubborn body fat.
* No calories are to be ingested during the fasted phase, though coffee, calorie free sweeteners, diet soda and sugar free gum are ok (even though they might contain trace amount of calories). A tiny splash of milk in your coffee won’t affect anything either (½-1 teaspoon of milk per cup at the most - use sparingly and sensibly if you drink a lot of coffee). Neither will sugar free gum in moderation (~20 g).
* The fast is the perfect time to be productive and get things done. Don’t sit around, get bored and brood about food.
* Meal frequency during the feeding phase is irrelevant. However, most people, including me, prefer three meals.
* The majority of your daily calorie intake is consumed in the post-workout period. Depending on setup, this means that approximately 95-99% (fasted training), 80% (one pre-workout meal) or 60% (two pre-workout meals) of your daily calorie intake is consumed after training.
* The feeding window should be kept somewhat constant due to the hormonal entrainment of meal patterns. We tend to get hungry when we're used to eating and maintaining a regular pattern makes diet adherence easier. If you're used to breaking the fast at 12-2 PM and ending it at 8-10 PM, then try to maintain that pattern every day.
* On rest days, meal one should ideally be the largest meal, as opposed to training days where the post-workout meal is the largest meal. A good rule of thumb is to make meal one on rest days at least 35-40% of your daily calorie intake. This meal should be very high in protein; some of my clients consume more than 100 g of protein in this meal.
* When working with clients I am always open to compromising on the above rule. If your preference is to eat a larger meal in the evening instead of noon, or whenever you break the fast, it's no great harm. Some people prefer to save the largest meal on rest days for dinner with their family instead of having a large lunch and that's fine by me if it makes them enjoy and adhere to their diet better.
* Macronutrients and calorie intakes are always cycled through the week. The specifics depends on the client's ultimate goal: fat loss, muscle gain or bodyrecomposition. The details will be revealed in the book. Generally speaking, carbs and total calorie intake is highest on training days. On rest days, carbs are lower and fat is higher. Protein is kept high on all days.
* Here are the supplements I recommend everyone to take on a daily basis: a multivitamin, fish oil, vitamin D and extra calcium (unless dairy is consumed on a regular and daily basis).
* For fasted training, BCAA or an essential amino acid mixture is highly recommended. However, if this feels like too much micromanaging or simply questionable from an economic standpoint, you could also make due with some whey protein.
* People sometimes ask me which protocol is best. I tend to look at things from a behavioral perspective first and foremost, so my reply to that is to choose the protocol best suited to your daily routine and training preferences. When dealing with clients I make the choice for them. If you work a 9-5 job and your only option is to train after work, training fasted is generally a bad idea and I always choose the one or two meals pre-workout protocol.
* Even from a physiological perspective, each protocol has it's own strengths and theoretical benefits. With "physiological perspective" I mean in terms of nutrient partitioning, fat loss and muscle growth. This deserves an article on it's own. I have some interesting and compelling arguments that I think are very unique.
PROTOCOL THAT I'LL BE FOLLOWING MOST OF THE TIME
Training is initiated on an empty stomach and after ingestion of 10 g BCAA or similar amino acid mixture. This "pre-workout" meal is not counted towards the feeding phase. Technically, training is not completely fasted - that would be detrimental. The pre-workout protein intake, with its stimulatory effect on protein synthesis and metabolism, is a crucial compromise to optimize results. The 8-hour feeding phase starts with the post-workout meal.
11.30-12 AM or 5-15 minutes pre-workout: 10 g BCAA
12-1 PM: Training
1 PM: Post-workout meal (largest meal of the day).
4 PM: Second meal.
9 PM: Last meal before the fast.
Calories and carbs are tapered down throughout the day in the example above.