Posted on December 16 2019
Time to Read: 8 Minutes
I have been hearing about intermediate fasting for quite sometime now and had to give it a try. Firstly, intermittent fasting (IF) is a very popular “diet/ lifestyle” concept, where you spend periods of time lasting from 14-20 hours not eating. Now this may sound very restrictive, but actually it really is not. My problem was really not the fasting part. I did the 16/8 hour fasting/ eating window for my trial. I was fasting from 6pm to 10am (sleeping most of it really).
The science behind this is simple. During the eating window, glucose is absorbed and used as a source of energy. Considering I still exercise two times (morning cardio and afternoon weight training), ergo using the glucose for the energy I require for pumping iron. During your fasting period, the blood glucose level in the body decreases and fat cells are oxidised as a source of energy. Intermittent fasting also puts you in a state of ketosis (just like in keto diets where fat cells are used to fuel the bodily functions) without all the side effects that come from dropping fibre and carbs on a keto diet. Undoubtedly, any form of fasting is good for you. Look at almost any religion of the world and they practice some form of fasting. Be it during Ramazan in Islam or during Lent for Christians.
Though intermittent fasting by itself works great in terms of reducing weight, dropping cholesterol and boosting insulin sensitivity, following an early eating window works even better.
This study (and multiple such studies) showed that even when accounting for eating the exact same number of calories and the same food, individuals who consumed the calories earlier on in the day experienced more benefits in terms of fat loss than those who consumed the same later on.
In this research study, without changing the calories input or increasing the exercise output, the average fat loss in overweight individuals with a restricted eating window was about 7 pounds in just a few months. In fact, this was one of the few weight loss studies where participants voluntarily chose to continue this pattern of eating even after the study was completed and sustained their fat loss.
Notice, this fat loss was without any change in activity level or caloric intake. If you want an estimate of how big the difference is, on an average if you consume a 500 calorie worth pizza for breakfast and the same exact pizza for dinner, you are likely to digest 50% better in the morning. That leaves 50% undigested calories to be stored as fat towards the evening than morning.
The longest living population in the world, the Seventh day Advantist, who live about a decade longer than the general population tends also to follow a similar eating pattern. With a heavy breakfast or lunch and prolonged fast, front loading calories might also hint towards longevity.
The first though that probably comes to your mind on why this happens is because you are more active during the day and burn up the calories better than at night. But this is not true by itself. Even with people who work night shifts, the glucose tolerance in the body declines as it gets darker. It is more to do with the circadian cycle of the body than anything else.
Having a fasting window for some people could also mean skipping a meal and consuming lesser calories. Multiple studies talk about the benefits of reducing calories and the positive effects it has on the body (apart from just fat loss). Reduced calorie diets have shown to increase life span in lab animals and also delay onset of predisposed age related genetic diseases. Reduced calories is associated with metabolic slowing and reduced oxidative stress on your cell which increases longevity. This study even goes on to show that just a 20% caloric restriction starting from age 25 and going upto age 52 could add upto five years more to your lifespan! Reduced calories of course means lower abdominal fat, lower cholesterol and triglyceride level, better insulin sensitivity and lower visceral fat. All of these also translate to longevity.
Now when I say “reduced calories”, I by no means am talking about a very restricted 1200 calories kind of diet. I am just talking about a 200-500 caloric deficit per day based on my activity level and BMR combined. As per my activity level and BMR, I should be consuming 2100 calories per day to maintain a caloric surplus. Since I am on a fat loss program, I aim to consume anywhere between 1650-1750 per day (trust me on a whole food plant based diet, that’s a lot of food!). Studies have also shown that if the caloric restriction is extremely vigorous, subjects tend to bounce back after the restriction is lifted and in fact gain more weight than they started with.
My expectations when I started IF were simple, to lose fat (not muscle mass), not crave in to eating late night snacks, improve overall digestive health and help clear up my skin and stomach. I would also not recommend anyone try IF for long periods of time if you are living in a chronic stress environment as this may effect your overall metabolic rate. This is especially more applicable for women than men.
So this was exactly how I did IF:
Wake- up: Wake up time was around 7- 8 am immediately followed by empty stomach morning cardio anywhere between 20-40 minutes.
IF still means you can eat anything below 50 calories but I did not eat anything post cardio. I did however consume LOTS of water and liquids before 10 am. Mostly hot water with cloves (to kill bad gut worms/ bacteria) and matcha tea powder with water. Also once every 15 days I had a tsp of activated charcoal (again for gut health).
First meal (10am)– Breakfast bowl with either oats/ quinoa/ madhira/ ragi (one grain or pseudo- grain) and a fruit like apple/ banana/ sugar apple/ papaya. Topped with Goji berries, cacao nibs or chia seeds (any one or two types of nuts or seeds) and half scoop vegan protein powder. I sometimes also add in maca/ acai/ matcha/ cacao powder.
Meal 2 (11am): Beetroot and spinach smoothie OR sprouted mung beans with nooch OR sweet potato.
Strength Training: 12pm to 2pm.
Meal 3 (2pm): Brown rice (always) with any legumes/pulses and fibrous veggies. Tofu sometimes.
Meal 4 (4pm): Protein shake with dates or soy milk/ chia seeds and a fruit. Boiled kidney beans or nuts sometimes.
Meal 5 (5pm): Bowl of veggies (fiber part of dinner)
Meal 6 (6pm- last meal): Buckwheat OR quinoa OR amaranth with adzuki/ kidney beans or chickpeas. Basically one type of whole grain and one type of beans/ lentils.
I had to eat multiple meals in a short span of time to reach my daily calorie goal and this can be challenging for a few people. But for someone on a fat loss program, this could work in your advantage. A lot of times I was eating my snacks even when I was not hungry to reach my caloric goal. Because I am used to eating small portions instead of large main meals, this was the only way I could get enough calories in. For someone looking to build muscle mass and stay in a caloric surplus, this might not be the best option. Although, some research does also point to the fast that fasting boosts testosterone.
Besides this, almost every day of my first week of trying IF was a family movie night. Meaning, late night nachos- guac and popcorns (pizza sometimes too). Since I was committed to IF, I did not taste even a bite of any of this. Having an eating window stopped me from junk late-night- mindless- empty- calorie eating. Also, inspite of my water intake being very high, I woke up every morning to a flat belly, this was probably because I ate a few hours before sleeping and giving my body enough time to digest. Read this article talking about how the same calories consumed in the evening adds to body fat 50% more than when consumed in the morning.
Not much change in my digestion or skin, but just a month is a very short time to say anything. I also got rid of a bloated belly and about 2 kg weight in a month (assuming most of it was water weight).
My recovery was marginally better. This was because I went to bed empty stomach and my digestive system was resting and my body could better focus on recovering muscle fibres. I did not see any much difference in my strength gains (lifting almost similar weights). But cardio endurance got a little better. Could sustain longer without feeling fatigue.
So in conclusion,
I would say I could do better with a little better planning, I just woke up one morning and dove into it. If I can make my main meals calorically more dense, I would probably not have to snack so much in between.
Also great to try if you are trying to lose weight and are on a caloric deficit or restraining calories. Since eating window is so small, you will still feel like you are eating so much but are actually not. This lifestyle change would be perfect for people who are not very good with portion control type of diet. With a smaller eating window, you end up automatically missing one meal and eating less.
Do keep in mind though that if you are going for an extreme caloric restriction to lose weight, chances are that you will bounce back and gain the weight once you go off IF.
Should you do it,
If you are glucose sensitive- this is not suggested without proper guidance. Ironically, fasting does improve glucose sensitivity though. I guess its a good thing to try if you want to get of a plateau. Plus if you have a habit of mindless eating. I will probably slowly reduce my IF time instead of going back to 11 hours directly. Maybe try and find a middle sweet spot that works for me best. I would suggest trying it for two weeks atleast and then listening to your body signals. Also, if you weight train early morning, there is really no rule that says 6pm- 10am, choose a time that suits you. But always eat around your main workout.
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