Be mindful of how much energy you are consuming. There are plenty on online calculators that will help you work this out as a good calculation will use your age, gender, height and weight. If in doubt then roughly 30-35 kcals/kilogram body weight is a rough guide to get you started. For a 70 kilogram person this equates to 2100 – 2450 kcals daily. Obviously this is a rough guide because if you train or are very short or very tall this will over or under estimate what you may actually need.
Try to consume nutritious food during the non fasting window due to a limited time to eat. Eat healthy foods that meet your estimated energy requirements. If you are trying to lose weight then calculate for this also. It can be difficult to consume your daily energy requirements in half the time you would normally and as a result you probably can’t = hence you lose weight. If weight loss is not your goal then you will need to maximise your food intake in your eating window.
Do you really burn fat when you are fasting?? If you consume carbohydrate during your non-fasting window it is unlikely you are burning much fat in the fasting period, as this requires you to be in a carbohydrate depleted, fat adapted state or nutritional ketosis. You will burn some fat as fuel in the fasting period, but not as much as a fat adapted person. If you want to be in ketosis you don’t have to fast to achieve this, it’s a different dietary principle; however when you are in ketosis it is possible to fast a little easier as your body can efficiently run on ketones (broken down from fat stores to release energy) and use body fat stores for energy…
Yes you can train when fasting and it is encouraged if you are able to. Exercise combined with fasting may mean that you glycogen stores are depleted faster and therefore more fat is used for fuel. You should consume water throughout the activity and fasting window as this could be very dangerous for most people…you need to replace your sweat. During Ramadan food and water is not consumed during day light hours and therefore training programmes are usually adapted to be in the evening after Iftar or early morning light sessions after Sahoor; but hydration will be an issue as after an early morning session as no fluid is allowed. It is usually recommended evening training sessions for Ramadan before or after Iftar. Some training Intermittent Fasting protocols recommend that if you are during the fast then, some 100% whey protein consumed after a session maybe allowed…so not a typical fasting protocol but another point to consider for athletes who want to try intermittent fasting, as weight loss may not be a goal and lean body mass gain is.
Actually there is nothing wrong with fasting for most people. If you take medication or have a medical condition where you need regular amounts of food and fluid throughout the day then it is not recommended. Fasting is a way of life and for most people helps them achieve and maintain a healthy weight. As long as you eat nutritious food in the non-fasting period and can achieve your health goals it should be fine to do, if in doubt check with a health professional. Just like any eating plan Intermittent Fasting is not for everyone, but for some it can be life changing and an easy method for calorie control, a for a feeling of cleansing and improved energy.
If you want to learn more, then please have a look at our fantastic presentation on intermittent fasting by Georgia Fassoulidis.