In This Article, You'll Find:
What is Intermittent Fasting?
By definition, this means eating for a certain period of hours and then fasting(not eating) for a set number of hours. The theory behind intermittent fasting(IF) is that humans did not used to live in environments where we had access tofood 24 hours a day like we do now — rather, our ancestors evolved in a timewhen food was relatively scarce, and they had to function at their bestphysically and mentally often in a fasted state.2
In modern times, this translates to not eating for many hours in a day, workingout in a fasted state, and then limiting your meals during the day to a shorternumber of hours than your fast. The 16:8 intermittent fasting diet is oneexample of this.
What is the 16:8 Diet?
The 16:8 intermittent fasting diet limits eating to 8 hours a day and requiresfasting for the remaining 16 of 24 hours. Although 16 hours seems like a longtime, this includes time spent sleeping. The theory is to wake and work out in afasted state, which forces your body to draw upon fat stores for energy.2
You should consume reasonable meals throughout your 8 eating hours. Whilefasting, you should drink water, and some choose to include unsweetened tea,coffee, orBCAAs /pre-workoutin the mornings before exercise.
What are the Benefits of Intermittent Fasting?
It is a popular topic in research and there have been some animal studiesshowing beneficial impacts on weight loss and cardio-metabolic risk factors(like blood pressure, cholesterol, and insulin-resistance).3 Somestudies show a greater benefit from intermittent fasting than from a continuouscalorie restriction style diet.4
Additional experimental models predict potential positive impacts ofintermittent fasting to extend to age-related disorders, although more researchin these areas is needed.2
There have been studies showing that performance does not suffer in a fastedstate, and some intermittent fasting dieters claim that they have even moreenergy and mental clarity when following a 16:8 style diet.5 There’sless mental effort and stress dedicated to meal planning and prepping. Followinga 16:8 diet is sometimes referred to as “lean gains”, building on theory ofburning fat and calories while working out in a fasted state.1 Thismethod of fasting has been shown to be effective in limiting calorie intake toreduce fat while still maintaining performance and muscle tissue.1
Practical benefits of intermittent fasting include less time spent preparing,eating, and cleaning up after meals (versus a diet of six small meals a day, forexample), and its flexibility. You may only need to plan for two meals and theycan be larger portions. The major guidelines for the 16:8 diet rely on thetiming of meals and not exactly which foods you need to eat. Intermittentfasting doesn’t require calorie- or macro tracking, but can be used inconjunction with any healthy diet pattern you already follow. For those whostruggle with mindless snacking throughout the day or boredom eating at night,having a strict eating schedule can prevent those unnecessary calories that canlead to weight gain.
How to Intermittent Fast Safely
To follow the 16:8 intermittent fasting plan safely, you need to make sure tostay well hydrated while not eating by drinking plenty of water. Coffee orunsweetened green tea may be consumed in the morning to help fuel your workout(or you can use Pre-Workout), as long as you are not adding any cream orsweeteners. There is some thought that consuming a BCAA supplement right beforeyour fasted workout can help to prevent muscle loss.1
When you're in the 8-hour eating period, it's crucial to obtain high qualitymeals containing all of your necessary macros (protein, carbs and fat) andvitamins/minerals for the day. Be sure to stay hydrated and meet your proteinneeds to prevent any lean muscleloss. It may be more difficult to obtain adequate calories in a short period oftime, which may lead to weakness or dizziness.3
Additionally, be cautious of not overeating just because you know you haveanother 16-hour fasting period ahead. Intermittent fasting is designed to keepyour body in deficit for the day as a whole, so be cautious not to binge onhigh-calorie junk foods.6
While there are promising outcomes of intermittent fasting, there’s anopportunity for further research related to performance and health benefits.3Many of the studies thus far were on overweight- or all-male subjects. If youhave blood sugar control issues, like diabetes or hypoglycemia, intermittentfasting may not be a good fit. Alternatively, if you are pregnant orbreastfeeding, or take medications that are taken with food, speak to you doctorbefore trying the 16:8 diet.
Take Home Message
Like any other diet, 16:8 intermittent fasting can be an effective strategy forweight loss and exercise performance without requiring counting calories ortracking macros.4 The 16:8 diet can also decrease fat mass whilepreserving muscle, leading to lean gains.3 While more research isneeded, it shows promising results for body composition, performance, andhealth-related outcomes. Intermittent fasting is one option for limiting totalcalorie intake when trying to lose weight and maintain muscle. When practicingthis diet, remember to stay well hydrated, even while fasting, and to choosebalanced, healthy meals during the 8-hour eating period. Speak with your doctorabout any concerns before trying out this plan.
