Of all the diet craze that’s circulating the fitness industry today, intermittent fasting is certainly one of the most popular. While fad diets like keto, carnivore, vegan, IIFYM, and fasting can be effective, they are generally way overhyped.
The reason any diet works (for weight loss) is that it creates a calorie deficit. There is nothing magic about not eating meat. There’s nothing magic about not eating carbs. There’s nothing magic about skipping breakfast and eating all of your calories in the afternoon or evening. The “magic” in some of these diets lies in the fact that they make it easier for people to consume fewer calories than they burn.
Keto works for some people because fat and protein are quite satiating which leads to less desire to overeat. The Carnivore diet is so high in protein that it's difficult to eat too many calories and because you have so few food options compared to a more standard diet. Your only choices for food are meat, eggs and fish. Vegan diets (at least the “healthy” ones) are high in fiber and low calorie-density foods that people tend to eat less. IIFYM (if it fits your macros) basically allows people to eat the foods they want as long as they’re eating within their macro (and therefore calorie) requirements.
Fasting is used in a few different ways that all can be quite effective. Many people will fast for longer periods of time but only occasionally. For example, two or 3 times a year you’ll fast for 2-7 days. This can be great for health, so long as your diet the rest of the year is mostly healthy. Although you may lose a bit of muscle acutely, the long term muscle loss effects are quite negligible, and are outweighed (in most people’s opinion) by the health and longevity benefits of a longer fast. Other people will fast for certain periods of time each week. For example, every Sunday night they’ll finish their last meal at, say 7 pm, and not consume any calories till 7pm monday night. This is the weekly 24 hour fasting method. Others will fast daily, usually for 14-20 hours, and utilize an “eating window” in which they consume all of their daily calories.
Although some argue that not eating for anything less than 24 hours isn’t truly “fasting”, there are still many benefits to having a shorter eating window. People who consistently utilize a 16-18 hour fast may enjoy decreased stress around food and feedings, less meal prep, more time to accomplish tasks and work during your fast, potential fat loss (if you’re in a calorie deficit), ability to eat larger meals if you prefer them, more mental clarity, reduced systemic inflammation, and better digestion. Autophagy, or cell death and rebirth, is a buzz-word in the intermittent fasting community. It essentially means that your damaged cells and mitochondria die off and new healthy cells are generated. This is a good thing, and has been shown to reduce your risk of cancer, improve brain health, and increase longevity. Although shorter 16-18 hour fasts provide far less autophagy benefits than longer multi day fasts, studies show that it may still be present and beneficial.
In this blog post, the fasting technique I’ll focus on is that in which you’ll have a daily eating window of 8 (+or-) hours. The most commonly used time frame for this is from 12 noon to 8PM but depending on your lifestyle and social situation, any 8 hours of the day will produce similar benefits. All of your daily calories will be consumed inside this time frame. The other 16 hours of the day will be spent fasting, or refraining from consuming any calories. Certain non-caloric beverages like water, diet sodas, coffee and tea are allowed, but anything containing calories is out.
Fasting has a considerable amount of benefits. Disclaimer: using fasting as your primary method for weight loss, while effective, can lead to problems over time. If you skip meals and starve yourself with the sole purpose of losing weight and getting leaner, the potential negative effects may outweigh the benefits.
My recommendation is to change your mindset on why you’re fasting and focus on the benefits and techniques below. If you’re able to do this, the secondary result will likely be weight loss and improved body composition, along with a healthy relationship with food.
Benefits of Fasting
Only eating during certain times of the day allows you to have more freedom and to stress less about getting your next meal. Countless studies have shown that not eating for 16+ hours does not lead to muscle loss, or a slowing of the metabolic rate. If you skip breakfast and don’t have to think about eating till later in the day, it can free up more time in the morning to accomplish your tasks, work, and perhaps train. Additionally, if you enjoy meal prepping, you’re preparing at least 7 fewer meals per week (assuming you meal prep breakfast every day). The mental burden of always having food around can be a tough hurdle to get over when you first start fasting, but eventually, you’ll get accustomed to it and very likely start enjoying the freedom.
If you're someone who enjoys snacking all day long, fasting might be difficult for you early on. However, if you’re like me and you enjoy eating larger meals, fasting is great. If you’re only able to eat during a certain time window, the amount of food you’ll need to consume per meal is likely going to be higher. This leads to more flexibility and more freedom to eat till you’re fully satisfied
Improved Relationship with Food and Hunger
Once you’ve become accustomed to fasting, you’ll begin to learn what it truly feels like to be hungry. The majority of people who have never fasted before don’t know what true hunger feels like. Hunger is different from cravings, and unless you’re very self-aware and experienced, it’s tough to know the difference. Hunger means you’ll eat anything. Cravings mean you want to eat something specific (and usually unhealthy) but if offered something nutritious (but less delicious) you’re likely to pass. If you think you’re hungry and I were to offer you a piece of chicken breast, but the chicken breast doesn’t appeal to you, you’re not hungry. Fasting can help you not only with differentiating hunger from cravings, but it can also teach you about your tendencies when you’re dealing with stress. Many people turn to food when they are stressed, anxious, depressed or bored. This is completely normal and you’re not a bad person if you do this. But if you practice fasting, you’ll need to learn to deal with your feelings in a different way. This can be very valuable for someone who struggles with stress-eating.
It’s important to remember that being a bit hungry is perfectly fine and healthy. Being hungry is different from starving yourself. You should not be fasting until you’re uncomfortably hungry. As long as you’re eating enough calories and nutritious foods during your eating window, most people have no problem fasting for 16-18 hours a day once they’ve become accustomed to it.
Harder to Overeat
The main reason this type of eating leads to weight loss is that when you only have 8 (or less) hours to eat, it can be more difficult to consume too many calories each day. That said, you’ll need to ensure you’re eating mostly whole, natural, nutrient dense foods. If you’re consuming processed, highly palatable foods throughout the majority of your eating window, the likelihood of overeating is high. Focusing on lean protein, healthy fats, and for some people, healthy carbohydrates is a must. Calories still count just as much as they do when you’re not fasting.
Tips for Success
Breaking the Fast
You should consider breaking your daily fast with something easily digestible and nutrient dense. If you’ve been fasting for 16 hours or more, ensure you’re not breaking the fast with a massive high calorie meal or heavily processed foods. I like to use an analogy comparing this to working out. If you’re going to the gym to do heavy squats, you’re not just going to put 400 lbs on the bar and go to town. You’re going to warm up and prepare your muscles, joints, and nervous system for the heavy load. The same thing can be said with breaking a fast. Ease into your eating window with some vegetables, a bit of protein and healthy fats. Once your digestive system is “warmed up”, you’re welcome to have a bigger meal. This will also help deter you from binging. If you’re starving and you start your eating window with processed food, you’re way more likely to go overboard.
During a fast you must hydrate, and not just with water. When you fast, your body rids itself of fluids at a higher rate than when you’re fed. The fluids you’re peeing out contain electrolytes. If you’re only drinking plain water during your fast you’ll likely experience light headedness, brain fog, low energy, cramps, and intense hunger. One of the biggest game changers for me (and many fasting practitioners) is the addition of electrolytes during a fast. This is especially important if you train during your fast. I recommend LMNT electrolyte powder in your water, at least around training. If you want to go the less expensive route (totally fine) you can just add some salt to your water throughout your fast. Along with salt, fresh lemon juice can help the water taste better and also help stabilize your blood sugar.
Ensure You’re Eating Enough
If you’re trying to gain muscle, this one is obvious. It’s impossible to gain significant muscle or strength if you’re not eating enough. But even if you’re looking to lose weight, you must ensure you’re eating enough during your eating window (although still remaining in a slight deficit). Why? If you consistently undereat too significantly, your energy levels and performance the following day will suffer. Not only that, but your metabolism will slow down over time. Fasting itself does not cause considerable metabolic slow-down. But if you regularly fast and undereat, over time you’ll have to continue to cut your calories even further to avoid weight loss plateaus. It’s important to prioritize eating the right amount of calories for your individual needs. Some days this may be more difficult than others, And it’s ok to have occasional lower calorie days (or occasional higher calorie days). Just don’t make it a habit.
Training while fasted is highly individual. Some people have no problem with it (and actually prefer it), while some people despise it. I recommend at least trying it out for yourself so that you can plan your training sessions accordingly. If you try it out a few times and find that your performance takes a big hit, move your training sessions to inside your eating window (after you’ve eaten a meal). If you love it, stick with it. Your body will use fat as its main fuel source and your circulating amino acids from the protein you’ve consumed the day prior are sufficient for muscle recovery. If you have specific muscle building goals, or you’re interested in maximizing your physical performance, while you can still get results from training fasted, you may be better off eating something prior to training. If you prefer training fasted, try to time your training so that your eating window opens up relatively soon (within 1-3 hours) after training so you can maximize protein synthesis and aid in recovery and muscle building. I.e. If you’re fasting till noon, perhaps you train from 10-1130 and then eat your post workout/break-fast meal. Another great option (and one I often use) is to only fast on rest days or light training days. I personally notice that I’m able to push harder in high intensity workouts if I’ve eaten prior. I’ll often extend my fast to 18-20 hours on low activity days because I find it easier to refrain from eating if I’m not training hard and moving around a lot. See what works for you and don’t overthink it. 1 or 2 days per week of fasting can still be beneficial!
Caffeine. Using caffeine can help with mental clarity, energy, and appetite control. Ensure you’re not mixing caloric sweeteners into your caffeine. Black coffee, plain green or black tea, caffeine pills, and zero calorie energy drinks (in moderation) are totally acceptable while fasting.
Sitting around and being bored can often make fasting difficult. You’ll want to keep your mind and/or body occupied while fasting so you’re not sitting there thinking about food all day. I find that I experience a cognitive boost while fasting, so I take advantage of it by working, writing, brainstorming, and producing content. Other great activities to keep you occupied are walking, light cardio, household chores, yard work, or spending time with family. If you stay occupied, you’ll be surprised some days at how your eating window just sneaks up on you.
Don't Major in the Minors
Some days you may start eating a bit early. Other days you’ll lose track of time and “forget” to eat when you usually do. This is totally fine, normal, and not something to stress about. This diet should decrease stress in your life, not add to it. You shouldn’t aim to be perfect every single day. Consistency is key.
Intermittent fasting can be a great way to control your eating, reduce your stress around food, enjoy larger portions, and even increase daily productivity. All nutrition rules still apply, and just because you’re spending a large portion of your day not eating, doesn't mean something magic occurs that enables you to go crazy during your eating window. It is certainly not the best practice for everyone, but many people find it enjoyable and simple. If you do it for one or two days and hate it, it’s important to remember that it may take a week or perhaps longer to get used to. Try it out sometime if it appeals to you.
Thank you for reading! Have you tried fasting? What are your most profound fasting benefits? What strategies and techniques do you implement in order to make the fast easier and more effective? Leave a comment below!