Intermittent fasting for weight loss in men

If you’re a guy who’s having a rough time losing body fat, you’re not alone. 

Whether it’s a packed schedule, work, family, travel, getting older, or any number of other life demands, finding time for healthy habits can be hard. Plus, food tastes good.

So, a restrictive diet is off the table. It’s not good for you, and frankly, you don’t have the time or energy to be measuring your food or eating weird ingredients.

Luckily, intermittent fasting is a perfect option for busy guys who want to look, feel, and perform better — without fussing over their food.

Key takeaways

• Intermittent fasting is a good choice for busy guys because it’s simple and straightforward.
• Intermittent fasting can help men lose weight and/or build muscle while losing fat.
• Depending on where you’re starting out, intermittent fasting might help manage hormones like testosterone.[1]

(BTW, if you’re new to this whole idea of intermittent fasting and looking to get started, check out our guide to intermittent fasting for beginners. Then, once you’ve done that, take our SIMPLE quiz, and we’ll help you get Day 1 underway!) 

What’s intermittent fasting?

Before we dive into the specific benefits of intermittent fasting, we first need to talk about what intermittent fasting is. 

Intermittent fasting is a style of eating where you alternate periods of eating with periods of fasting (i.e., not eating). 

How long are those periods? That’s up to you — you’re the boss.

We’ll look more at how to pick your fasting schedule in a moment.

You already know how to do this.

You might be surprised to learn you already fast daily. When you sleep, you spend an average of eight hours in a fasted state. So, intermittent fasting just means extending that fasting period a bit longer. 

You can skip breakfast and eat your first meal later in the day, eat an early dinner, or choose to go an entire day without food. This nutritional change allows your body time to regulate your blood sugar, insulin, and cholesterol levels between meals. 

Plus, it can help you lose weight by using fat more effectively for energy while trimming off some mindless eating that most of us do throughout our days.

If you’re curious about whether intermittent fasting would suit you, take our SIMPLE quiz, and we’ll help you road test it!

What’s good about intermittent fasting?

Intermittent fasting is particularly helpful for men looking to lose weight.

One study found fasting helped participants lose 3–5% of body fat over a period of three to twelve months.[2] 

Lots of guys like the simplicity of intermittent fasting. There’s no confusing diet plan, no foods are “off-limits,” and you’re either eating or you aren’t — there are no complicated negotiations with your mind about whether you should have a snack. When it’s time to eat, you eat. When it’s not, you don’t. 

Intermittent fasting works with the life you have now.

Intermittent fasting can help combat the “high school memory” phenomenon. You know, your image of how things used to be — back in the days when you were younger, more spry, and might have had more hair …

Lots of guys keep eating as if they’re still 16. Except now they’re 46 and have a desk job, three kids and a dog, and a two-hour commute by car. Workouts? Who has the time and energy for that?

It’s easy for the pounds to pile on and that former energetic self to get buried.

And they wonder, is this it?

Nope. You’re not out of the game just yet, bud.

Intermittent fasting is a perfect option for men looking to take charge of their health, fitness, and weight.

Yes — you can feel that young-guy energy again … and it’s easier than you think.

Intermittent fasting can improve your metabolic health

Lots of guys avoid the doctor. For good reason — nobody wants to be told they have high cholesterol, the early signs of diabetes, or the arteries of a 109-year-old.

By helping you lose weight, trim your midsection, and improve your metabolic indicators like blood pressure, cholesterol, and inflammation, intermittent fasting can help you get a high-five from your doc.[3]

In particular, intermittent fasting can:

• lower inflammation
• lower blood pressure
• lower cholesterol
• reduce insulin resistance 
• reduce the risk of coronary heart disease

All that and a smaller belt size? Sign us up.

And if all these benefits have you itching to start your intermittent fasting journey, take our SIMPLE quiz and get started today!

Now, here’s one of the big questions on a lot of guys’ minds … 

Does intermittent fasting impact testosterone? 

Testosterone is a hormone found in both sexes, but men have much higher levels. 

Testosterone is responsible for what we think of as many traditionally male characteristics, including:

• development of penis and testes
• libido (sex drive)
• enhanced muscularity and bone strength
• deeper voice
• thicker body and facial hair

When testosterone levels get depleted, men may lose muscle mass, have more body fat, and feel low and “blah” emotionally. Low testosterone can increase the risk of type 2 diabetes, stroke, and heart disease.

Fasting can affect testosterone, but it’s not a simple cause and effect.[1] While we have some clues about the relationship between fasting and testosterone (as well as other hormones), we need more research to truly understand how it all works.

In men who have a significant amount of body fat: 

Testosterone may aromatize (aka convert) to estrogen, which means less free testosterone and more unwanted side effects like breast growth.[4–6] Additionally, higher body fat may go along with insulin resistance, which can also affect testosterone levels.[7]

Takeaway: In this case, especially if it results in fat loss and better insulin sensitivity, fasting might help regulate hormone levels. 

In men who are lean and very active:

Fasting may lower testosterone levels, especially if combined with a strict diet and intense training.

However, interestingly, one study of young men doing resistance training and intermittent fasting found that though testosterone went down, it didn’t seem to affect gym gains.[8–10] Intermittent fasting may be a good strategy for already-athletic men to get leaner, but it also requires careful attention to diet during the eating window. 

Takeaway: If you’re lean and active, fasting can also work for you … but watch your diet during your eating window to ensure you’re meeting all your nutritional needs.

Will you lose muscle? 

If you combine a good exercise program with intermittent fasting, you’ll likely get a double win of keeping your muscles while losing body fat.

Because it’s not a chronic energy deficit — in other words, you’re not “dieting” every day — intermittent fasting can work nicely with an exercise training schedule to help you achieve body recomposition: losing body fat while maintaining or even building muscle mass. 

There is a catch, though. Keep your protein intake high during your eating window. 

Logging your meals in your SIMPLE app will help you check that you’re eating enough.

Include a variety of high-protein foods like lean meats, poultry, fish and seafood, eggs, low-fat dairy, and plant-based options like tempeh.

Check out SIMPLE’s guide to intermittent fasting while bodybuilding if you want to learn more.

Popular intermittent fasting protocols for men 

There are many intermittent fasting styles used for weight loss that share similar benefits. The best protocol is the one that fits your lifestyle and goals. 

• 16/8 method: Fast for 16 hours and have an 8-hour eating window. 

• 5:2 method: Eat as you typically would five days a week and restrict your calories to between 500 and 600 the other two days. The 5:2 eating pattern is simplest for you if you don’t want to keep track of your eating windows daily and would rather track calories two days a week. 
• Alternate day or Eat Stop Eat methods: These protocols have you choose one to three days per week to fast (or eat very few calories), and then you’d eat as you typically would in between your fast days. The Eat-Stop-Eat method is a more aggressive form of fasting, and you may find it more challenging to stick to over the long haul, which is why we don’t usually recommend these. 

(And remember that intermittent fasting isn’t right or safe for everyone, so make sure to run your plans by your healthcare provider before starting!)

You’ll find lots of other ideas in the SIMPLE app — including a customized intermittent fasting timer that puts you in control of your intermittent fasting journey. Take our SIMPLE quiz and get started today!

SIMPLE’s expert opinion and final thoughts

If you’ve been contemplating how to begin your weight loss journey, intermittent fasting can be a great (and simple) first step. 

Intermittent fasting can help you keep more of your gym gains while stripping away the stuff you don’t want. Or, if you’re a “regular guy” who just wants to feel better and have more energy, intermittent fasting can do that, too.

Intermittent fasting can fight high blood sugar, insulin resistance, and the risk of developing diseases such as diabetes and coronary heart disease so you can live a full life.[3] 

Experiment and find a schedule that works for you. Remember, you’re the captain of this ship!

(Looking to find out even more about losing weight as a guy? Check out SIMPLE’s guide on weight loss for men.)

Frequently asked questions about intermittent fasting and weight loss for men

Is intermittent fasting safe for men?

Intermittent fasting can be safe for most men, but it’s essential to consult a healthcare professional before starting, especially if you have underlying health conditions.

Can I still build muscle while doing intermittent fasting for weight loss?

Yes, it’s possible to build muscle while intermittent fasting. However, make sure you eat plenty of protein and time your workouts around eating windows.

Will intermittent fasting decrease my energy levels and performance?

Some guys say they have more energy and mental clarity during fasting periods. Others sometimes feel more sluggish, especially at first as their bodies adapt. 

Performance might vary based on individual preferences, activity levels, and the type of fasting chosen.