How to Lose Weight After 40 (and Not Gain It Back)

Menopause and perimenopause make weight loss even more difficult for many women. I speak from experience. After turning 40, I felt I had to feel hungry and deprived 100% of the time to lose just 2-3 lbs a month. Then, if I ate enough to not feel hungry, I would gain it all back within days. It was so frustrating! Well, the good news is: I finally was able to lose 20 lbs at age 43 and not gain the weight back. In this post, I am going to share exactly how I did it without feeling frustrated and deprived.

How to Lose Weight After 40

A few key elements were essential in my success. Let me explain what they were.

Intermittent Fasting

Intermittent fasting is the number one method that has allowed me to lose weight and not gain it back in my 40s. But, there is a couple of things that made a big difference for me. I had tried intermittent fasting before, even in my 30s, but had never achieved the results I wanted until I did a few things differently.

Longer Fasting Window

The few times I had practiced intermittent fasting, I would do the most common form of intermittent fasting method, which is the 16/8 method (an 8-hour eating window). The problem is, you can easily overeat during an 8-hour window. To lose just one pound a week, you need a calorie deficit of about 3,500 calories. That’s 500 calories a day! If you have ever counted calories, you know that it’s pretty hard to get that kind of calorie deficit. For the average woman, who needs about 1,800 calories a day, that means consuming only 1,300 calories. Some restaurant meals provide over 1,000 calories, in case you didn’t know! For this reason, many women won’t be losing weight when eating during 8 hours. That was me!

How to Find the Right Intermittent Fasting Method

You have two option then:

  1. Fasting longer: You can try an intermittent fasting method like the Warrior diet or OMAD. The Warrior diet gives you a 4-hour eating window, while OMAD stands for one meal a day, which is typically a 1-hour fasting window.
  2. Fasting on specific days: A longer fasting window every single day may feel deprived and hungry for quite a while at first. If you are anything like me, you may find it impossible to stick do. That’s why you may prefer to start with other intermittent fasting methods that you don’t need to stick to every single day like the Eat-Stop-Eat method and the 5:2 method (my two favorite methods for beginners who want to lose weight).
  3. Check out my Intermittent Fasting 101 Workshop for more guidance.

Modified Fasting

If you have read my Top 7 Tips to Use Intermittent Fasting for Weight Loss, you already know about how modified fasting was a stepping stone to achieve weight loss without gaining the weight back.

How Does Modified Fasting Work?

The concept of modified fasting stems from the Fasting Mimicking Diet by Dr. Valter Longo. It’s a 4-5 day fast that involves a severe calorie restriction (you eat only about 40-50% your regular calorie intake). This type of fasting triggers autophagy, which is your body’s healing process. Not only this will aid with weight loss by releasing inflammation and normalizing your insulin level, but it will also help make you more metabolically flexible, which will make any form of intermittent fasting a lot easier.

I explain what it means to be metabolically flexible in my post Should You Practice Intermittent Fasting With or Without Keto?

The Keto Diet

The keto diet is a good option if you don’t want to go through the initial struggle of feeling hungry or “hangry” if you struggle much when you go without food. The keto diet stimulates fasting by reducing the amount of carbs so much (under 50 grams a day) that your body runs out of glucose and starts using fat stores to produce ketones instead.

I have been trying to understand the distinction between our bodies running on glucose and ketones. Whether you achieve it through fasting or the keto diet, there is no question that ketosis is beneficial in many ways. It will reduce your appetite and your cravings as well as make you feel more energetic and focused. Besides that, your cells produce less “waste” or reactive oxygen species (which cause oxidative stress) when running on ketones.

If you do the keto diet and you are a woman, I would just recommend that you increase the amount of carbs you consume to between 100 and 150 grams at least periodically (maybe 5 days a month at least before your period).

How to Not Gain the Weight Back

If you follow the guidelines I outlined above, you should be able to lose a few pounds each month. Don’t be discouraged when the weight loss slows down. I had months where I would lose 4 lbs and months where I didn’t lose any weight. It took almost a year to lose 20 lbs! The closer you are to your goal weight, the slower weight loss will be. It’s important to not lose sight of the fact that it’s a long-term project to improve your health as well. Once you understand that, you will greatly reduce the risk of gaining the weight back. I also have a few tips to share to help you stay on track and not gain the weight back.

Regular Weight-Ins

I don’t know why it takes a month of effort to lose two pounds and yet, you can gain back two pounds in a matter of days. Anyway, that’s just how it is. That’s why I recommend you weight yourself once or twice a week after you reach your goal weight. This way, you can make sure that what you are staying on track. If you gain weight one week, you know that you need to be more careful again. This might mean that you have been increasing the length of your eating window and you need to tighten it again or maybe you have been overindulging in some favorite treats. It’s easy to not notice when you gain 2-5 lbs. Regular weight-ins will help you avoid gaining back the weight you lost.

Warrior Diet Results

Longer Fast at Least Twice a Week

After you reach your goal weight, you may decide to stick to a 12-14 hour fasting window every day. If that’s the case, it’s a good idea to fast longer at least 2 days a week. I like to make sure I fast until 3 or 4 pm at least 3 days a week. When I do so, I notice that depending on how diligent I have been with my diet, sometimes it’s harder. If I have been eating more sweets, fasting feels more difficult. These longer fast days are like a “reset”.

Paying Attention to Your Body’s Cues

If you notice your appetite starts increasing again and you crave sweets again, it may be a sign that you need to fast longer or eat fewer carbs. I love the food freedom that intermittent fasting has been giving me. I don’t count carbs, I eat sweets when I want them and I rarely have to restrain my eating (during my eating window). However, sometimes I eat too many sweets or have too long of a eating window for too many days in a row and I find myself wanting to eat when I am not hungry. That’s a sign you need to be more careful if you don’t want to gain weight back.

Periodic Modified Fasts

I explained the benefits of a modified fast. Dr. Valter recommends them two or three times a year. I think that’s a worthwhile goal. These longer fasts help improve longevity, decrease inflammation, and contribute to your overall wellbeing.

Read Modified Fasting: How You Can Benefit From Fasting Without Giving Up Food for more info.

How to Lose Weight After 40 (And Not Gain The Weight Back) Video

In Summary

So, how do you not gain the weight back after you have put all this effort into your weight loss? Monitor how you feel and your weight regularly. By then, you will understand your weight patterns (for example how much you weight during your period compared to during the rest of the month), you will know your hunger cues, your energy level and you will be able to tell if you need to fast longer and be more strict again to avoid gaining weight back. This is the key to staying in shape and feeling great.