Fasting This Week? Here’s How It Can Help You Shed Pounds and Boost Your Health
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With Tzom Gedeliyah today and Yom Kippur coming up, we’re all gearing up for those long hours without food and drink. While fasting is a mitzvah, did you know that it can also be good for your body? Yes, you heard that right—fasting can do more than just cleanse your soul. It’s also a powerful tool for weight loss and overall health. So let’s break it down: what happens when you fast, and why can it actually be good for you (even if you feel hangry in the middle of it)?
What Happens to Your Body During a Fast?
When you fast for 12 hours or more, your body goes through some pretty fascinating changes. Here’s a peek at what happens behind the scenes:
- Bye-Bye, Quick Energy!
– During the first 8-12 hours of fasting, your body burns through its glycogen stores, which is basically the quick energy it gets from carbs. So, if you ate some challah or carbs before the fast started, that’s the first thing your body taps into for fuel.
- Hello, Fat Burning!
– Once that easy-to-access energy runs out, your body does something awesome: it starts burning fat. Yep, fasting shifts your body into fat-burning mode. This process, called lipolysis, happens after about 12 hours without food. Your fat cells break down and turn into energy to keep you going.
- Insulin Chills Out:
– Fasting helps lower your insulin levels, and that’s a good thing because high insulin makes it harder for your body to burn fat. Giving insulin a break makes your body more efficient at using stored fat for fuel. Score!
Ok, So Why Do You Still Feel Hungry if You Have Fat to Burn?
It seems unfair, right? Your body has plenty of fat stored for energy, so why does it still make you feel hungry? Here’s the deal:
- Hunger Hormones: Your stomach releases ghrelin, the hunger hormone, when it’s empty, which is why you feel hungry even if your body can technically use fat for energy. It’s your body’s way of saying, “Hey, we usually eat around this time—what’s going on?”
- Habit: Part of that hunger is just habit. If you’re used to eating at certain times, your body will signal hunger, even if it doesn’t need food. It’s your brain playing tricks on you!
- Mental Hunger: Fasting can mess with your routine, and that can lead to mental hunger. Sometimes, just the thought of fasting makes us focus on food even more!
Can Fasting Help with Weight Loss?
In a word: yes! But not just because you’re skipping meals. The main reason fasting works for weight loss is because it helps you create a calorie deficit. If you’re eating fewer calories than you’re burning, you’ll lose weight. Here’s how fasting helps:
- Fewer Opportunities to Overeat: When you fast, you naturally limit the time you have to eat, which makes it easier to avoid snacking or overeating. And let’s face it, late-night snacks can really add up!
- Fat Burning Mode: As we mentioned earlier, after about 12 hours of fasting, your body turns to fat for fuel. If you combine this with a calorie deficit, it’s a recipe for weight loss success!
- Metabolism Boost: Fasting can also help improve insulin sensitivity and boost your metabolism over time, making your body better at burning fat and using energy efficiently.
But What About Those Headaches and Crankiness?
We’ve all been there: halfway through a fast, and suddenly you’re hit with a headache and a serious case of the grumps. Here’s why that happens and what you can do about it:
- Low Blood Sugar: As your blood sugar drops, your body is trying to adjust, and that can lead to headaches and irritability. Your brain loves glucose, and when it’s running low, it lets you know!
- Dehydration: Fasting sometimes means you’re not drinking as much water as you normally would, leading to dehydration. Always make sure to hydrate really well before you fast.
- Caffeine Withdrawal: If you’re a coffee or tea lover, skipping caffeine can lead to some serious withdrawal symptoms, including headaches and fatigue.
How Water Weight from Rosh Hashanah Feasting Ties Into Fasting
Post-Rosh Hashanah scale shock? Don’t sweat it—it’s just water weight, not fat! Here’s why:
- Carbs Love Water: All that challah and kugel? Your body stores those carbs as glycogen, and for every gram, it hangs on to 3-4 grams of water. That’s why you might see the scale jump a few pounds after Yom Tov—it’s usually water, not weight gain!
- Salty Bloat: Rosh Hashanah meals can be loaded with sodium, making you retain extra water. That puffiness? Totally normal. Drink up this week, and it’ll flush out.
- Water Weight = Temporary: The good news? This isn’t fat—it’s just your body holding onto water. After fasting, your glycogen stores will drop, and so will a lot of that extra water. Poof!
Remember, the real game is a calorie deficit for fat loss. So don’t let those post-holiday water fluctuations fool you—fasting will help your body reset!
Is Fasting the Magic Bullet for Health?
Fasting isn’t just about weight loss; it offers a host of other health benefits, too:
- Better Insulin Sensitivity: Fasting helps reduce insulin levels, which can improve your body’s ability to handle blood sugar and lower the risk of type 2 diabetes.
- Cellular Cleanup: During a fast, your body kicks into autophagy mode, which is basically cellular spring cleaning. Old and damaged cells are broken down and recycled, leading to better overall health.
- Mental Clarity: Many people report improved mental focus and clarity during fasting periods. Once your body gets used to using fat for energy, you might experience fewer energy crashes and better concentration.
Beware of the Break-Fast Trap!
Now, here’s a big NOT—do not undo all your hard work by cramming in everything you can find at break-fast! Yes, we know it’s tempting to go wild after a full day of fasting, especially when there’s Bagel, lox, and orange juice, kugel, and all the good stuff right in front of you. But overloading your body with carbs and heavy food all at once can actually leave you feeling worse, not better.
What Happens When You Overdo It:
- Blood Sugar Spike and Crash:
- When you fast, your body’s blood sugar levels drop. If you suddenly flood your system with high-carb foods (hello, challah and pastries!), your blood sugar skyrockets, only to crash soon after. This can leave you feeling sluggish, tired, and even hungrier.
- Overeating and Bloating:
- After a day of fasting, your stomach shrinks slightly. Eating too much, too fast can lead to bloating, discomfort, and feeling overly full. Instead of relief, you’ll just feel like you need to lie down (and not in the good, post-Yom Kippur way! When you have the sukkah to build).
- Delayed Digestion:
- Your digestive system has been on a mini-vacation all day, so overloading it with rich, heavy food in one sitting can be a lot for your body to handle.
How to Break the Fast the Smart Way:
- Start light: Break the fast with something gentle, like a warm bowl of soup or a handful of nuts. This will help wake up your digestive system slowly and prevent any major crashes.
- Hydrate: Drink water before diving into the food. Often, dehydration makes you feel hungrier than you actually are.
- Take it slow: Instead of cramming everything into one meal, enjoy a slow and balanced break-fast. Start with a little protein and healthy fats, then ease into the carbs if you want.
Remember, break-fast is about re-nourishing your body—not shocking it with a food overload!

Thank you for an informative article! Just one question. Is it true that when the body feels hungry, it gets the message to store fat instead of burning it, “in case of emergency “? If so, how does that work with intermittent fasting? I finish eating for the day at 7, then by 11 I’m really hungry. If I don’t eat something will my body learn to hold onto the food the next time I eat?