lose belly fat

How to Lose Belly Fat in Your 30s and 40s (Backed By Science)

Here are the keys to shedding those pounds

If you want to lose belly fat in your 30s and 40s, there are effective ways to go about it.

Here’s the uncomfortable truth:

As we grow older, our bodies don’t burn fat from our midsection as they used to when we were younger.

It seems that the area around our belly becomes a magnet, attracting flabby bags of fat with each passing day.

I don’t know about you but I sometimes look in the mirror recently and wonder what happened to my teens and twenties body.

But there’s some good news: yes, you can permanently lose belly fat.

In this post, we’ll discuss the research on weight loss and specifically how to lose belly fat in your 30s and 40s.

Finally, we’ll share some tips on how to keep your midsection free of excess fat.

Let’s dive in!

Factors for losing belly fat

In our teens and twenties, you can agree that body strength is growing and at its peak. 

There is so much energy available to get rid of excess fats when they become unwanted. 

There are two important factors to understand if you’re keen to lose belly fat:

  • Muscle loss
  • Metabolism

Let me explain these in detail.

1. You’ll need to prevent muscle loss

The first factor is muscle loss. Muscle loss is common as you age. 


After the age of 3, you lose muscles between 3 and 5 percent per decade. And men will lose up to 3 percent of their muscles during their lifetime. 

Muscle loss means less mobility. And that also means a low level of physical activeness which is closely related to a sedentary lifestyle. 

Mobility or activeness is one of the ways our bodies use up the energies stored in fats. 

So imagine what happens if they keep on getting piled up without being used.

2. You’ll need to improve your metabolism

The second important factor you need to understand to help lose belly fat is metabolism.

You might have heard a friend or colleague say something to the effect that they have low metabolism. And that is why they keep on weight.

There is some truth to it. Let me explain.

Metabolism is the process by which our bodies convert what we eat and drink to energy.

Our bodies constantly depend on this process to keep functioning, even when we’re resting.

Think about it, even at rest, your body still needs to breathe, circulate blood, grow and repair cells. 

The amount of calories you need for these life-dependent activities is called the basal metabolic rate.

This rate varies based on your age, sex, and body type.

So, with these two factors in mind, here’s the kicker:

To a large extent, you can prevent muscle loss and improve your metabolism.

How? Physical activity.

We will discuss more of this in a moment.

But for now, think of simple activities like morning yoga stretches. Or even standing (instead of sitting).

The more active you are, the higher your metabolism.

Now that we’ve clarified these two important concepts, let’s move on to discuss ways that you can gain more muscle and improve your metabolism. 

How to lose belly fat in your 30s and 40s

Understanding these two factors can be the solution to getting rid of stubborn belly fat.

1. High-Intensity Interval Training (HIIT)

Many doctors and trainers treasure high-intensity interval training (HIIT) as an effective way to lose belly fat. 

And there’s a reason.

One of the very first studies to examine the impact of HIIT and body composition was presented at the American College of Cardiology conference.

Researchers in that study found that:

Patients who practiced HIIT lost more body fat, gained more lean muscle mass and trimmed more inches off their waists—all of which play a role in heart health.

HIIT workouts involve short exercises that require a lot of energy with short resting time intervals. 

During HIIT, there is the production of lactic acid which helps to supplement the inadequate oxygen in the body. 

Adrenaline is produced alongside which helps to move fats resulting in the burning of fats and muscle build-up. 

After HIIT, the body is still in full metabolism mode trying to replace lost nutrients.

Your body’s insulin level is also sensitive at this time so there is no way it will store glycogen as fats.

What’s more?

All of these HIIT-induced changes in the body help to increase fat burning and energy expenditure several hours after exercise or working out.

And this, in turn, helps you lose belly fat

What is an example of a HIIT workout for losing belly fat?

Think of a short sprint, followed by a 30 seconds jog. And then another sprint.

Repeat this for 5 to 10 minutes and you will have a HIIT circuit that’s working in your body.

The good news with HIIT is that you don’t have to stay in the gym for hours. HIIT eliminates the common excuse of “I don’t have time to go to the gym.” 

Here are a few safe HIIT ideas to get you started.

Consider a 10 or 20 minutes workout that includes 10 to 20 seconds of any combination of the following (with 10 seconds rest in between):

  • Burpees
  • Pushups
  • Rowing on a machine
  • Cycling on a stationary bike
  • Air squats
  • Pull-ups

Once you’re advanced in HIIT, you can consider adding safe CrossFit workouts to improve your metabolism.

2. Strength training

Strength training helps build muscle mass and improve bone strength.

More muscle mass helps to burn more calories at rest. With aging, you lose muscle mass and strength training helps.

The key to strength training is volume. Volume in strength training, according to researchers, is measured in three ways:

  1. The total number of sets to failure
  2. The total number of reps (sets x reps) 
  3. Volume load (sets x reps x weight)

In biology language, the volume is the number of stimulating reps that you can perform for a muscle group in each set.

If you’re just starting, do it safely.

Start with small sets and small reps. And as you build more strength, you can add more sets and reps. Don’t rush it. Ever.

One of my favorite strength training techniques is the 5×5 technique. It includes a routine of:

  • Barbell Squat: 5 sets of 5 reps
  • Barbell Bench Press: 5 sets of 5 reps
  • Bent-Over Barbell Row (or Overhead Press): 5 sets of 5 reps

Here’s a video that gives you an over 5×5 workout. You can skip through it as it’s a pretty long video.

3. Intermittent fasting


Intermittent fasting is simply when you give yourself a specific window of time to eat during the day. 

It’s proven to be a powerful way to lose belly fat.

Contrary to what people think, intermittent fasting is not a diet. It’s just a change in the time you eat.

There is the 16/8 method which allows 8 to 10 hours for eating 2-3 meals. 

Source: James Clear

The rest of the day is fasting. There is also the 5:2 diet which says to fast two times a week.

You could also spontaneously skip meals from time to time. 

If you don’t feel too hungry to eat, just don’t eat.

And there is one where you fast the whole day and take a big meal in the evening within a four-hour window. 

The popular one is fasting every other day. You just decide not to eat anything during the day or just a few calories each day.

One study showed a 4 to 7 percent decrease in abdominal fats within 6 to 24 weeks.

4. Drink lots of water

There are so many benefits of drinking water first thing in the morning. But those benefits don’t stop only in the mornings.

In one study, 50 overweight females were put under a program.

Participants drank a glass of water before breakfast, lunch, and supper for 8 weeks.

The results showed a positive relationship between drinking 1.5 L of excessive water and weight, body fat, and appetite reduction.

Drinking lots of water helps to avoid unnecessary snacking. Don’t underestimate the constant need to be eating. The best is to prevent it.

Another study saw a drastic impact of calorie-burning where 12 people drank 500 mL of cold and room temperature water.

The point is: make it a point to drink a lot of water, especially before you eat which will suppress your appetite to overeat.

5. Eat more veggies

Remember metabolism? It is the process of converting food to energy. 

Eating energy-boosting foods, especially more vegetables (surprise, surprise!) can improve your metabolism.

Mushrooms are excellent to lose some extra flesh around the abdomen. They are low in calories and low carb.

They offer lots of fiber, potassium, vitamin B, iron, and even a little protein. 

These nutrients work together to burn those fats you do not want.

Carrots also do well with burning fats. They are rich in soluble and insoluble fiber as well as vitamin A.

Vitamin A is converted into retinoid which works against all fat cells and helps reduce belly fats. 

All these and more work against the build-up of extra flesh in the abdomen and help to reduce obesity.

Beans are also one of the foods that help to reduce belly fat. They fight against inflammation that causes the accumulation of belly fat.

There are broccoli, asparagus, cucumbers, pumpkins, and cauliflowers. Add them to your meals.

6. Reduce unhealthy carbs intake

Paying extra attention to your intake of carbohydrates is also fundamental if you want to lose belly fat. 

Where do you start? Cut down on refined carbs.

Refined or simple carbohydrates are sugars and refined grains that have their fiber, nutrients, and bran stripped off. 

They include:

  • pizza
  • pasta
  • white rice, and
  • sweet desserts

They get digested quickly and spike up our sugar level and build up fat around our waistline. 

Excessive intake of foods like these can cause type II diabetes. It’s unhealthy. Replace them with unprocessed carbs. 

The U.S. Department of Health and Human Services has some good advice: about 45 to 65 percent of your daily calories should come from carbohydrates. 

But that’s not all.

These calories should be from unrefined carbs. For example:

  • unrefined whole grains
  • non-starchy vegetables
  • legumes
  • nuts
  • avocados, and
  • fruits 

The unrefined nature of these carbs makes them difficult to digest.

This leads to a gradual rise in sugar levels. And they are rich in fiber which helps in weight loss, the burning of fats, and protection against type II diabetes.

And if you still want something sweet, eat blueberries.


Not only are they sweet, but blueberries also contain flavonoids. They are also rich in Vitamins A, C, and E, and carotenoids. 

7. Stop arbitrary snacking

We’ve all been there. We’ve been at that peckish state where we need something to chew or nibble on.

Snacking is the intake of light foods in small portions between regular meals. 

Most of the time, the meals we snack on are high in calories. And they add up very quickly to our belly fat troubles. 

One study found 36 lean men having their calorie intake increase by 40 percent. This led to an increase in their liver and belly fats. 

This is not to say that snacking is bad, but it all depends on what you eat. There are healthy snack alternatives to junk food you can consider.

For example, snack on protein-rich and high-fiber foods. Snack on whole foods too.

These include almonds, peanuts, water, fresh vegetables, and more.

8. Reduce sugar intake

Eating Too Much Sugar Health Risks

Most of our meals have a lot of sugar in them.

These sugars contain fructose which has a relationship with the acquisition of weight and belly fats. 

The bad news is most of them are artificial sugars.

And they contribute largely to the build-up of belly fat and chronic diseases. Type II diabetes and obesity are examples of those diseases.

Studies show a direct relationship between sugar intake and abdominal fat. Even natural sugars such as pure honey should be sparingly taken.

9. Get enough sleep

There is no high school class on how to sleep well, although the average human who lives up to 79 years will spend about 26 years sleeping.

It’s not surprising that when we become adults, we underestimate the importance of sleep.

If you want to lose belly fat or general body fat, you should sleep more.

Here’s why.

Inadequate sleep causes us to increase our calorie intake. 

In one study of 12 men who were allowed to have only 4 hours of sleep.

This sleep deprivation caused them to eat an average of 559 more calories the next day compared to when they had eight hours of sleep.

Sleep deprivation leads to an increase in appetite which leads to making bad food choices.

All these add up to build-up belly fat. If you’re having trouble sleeping, consider making little changes to help you sleep better at night.

For example, keep a regular sleep schedule or even adjust your sleeping position.

You can also consider taking afternoon naps or using white noise to help sleep better.

10. Stand more, sit less

As we mentioned briefly when we discussed metabolism, physical activity is important to fighting weight gain.

And it doesn’t have to be revolutionary activities.

Something as simple as standing instead of sitting can help you burn more calories and lose belly fat. How?

Standing helps reduce that occurrence as it burns a lot of calories while doing so. 

Moreover, choosing to stand more than sitting can also provide back pain relief, helping you to perform more advanced exercises to gain strength.

Take for example an estimate from the National Institutes of Health.


If you’re an average weight of 170 lb, here’s what you are likely to burn:

  • 134 calories sitting
  • 206 calories standing
  • 296 calories walking at a moderate pace
  • 341 calories walking briskly

11. Don’t try to diet

Your health is so important that it’s not worth any shortcuts. 

I can understand how tempting weight loss diet pills and diets and “programs” can be.

They promise us astounding results without us putting in any effort.

But you and I know life doesn’t work by shortcuts.

Like anything worth achieving, the journey to losing belly fat is a gradual process that will involve effort.

You will need to constantly put in the work to see the body you want.

A lot of dieting programs fail because they are not sustainable.

It’s not surprising that in the short term, dieting may help to do away with a few pounds.

But (with a big B) in a few years, you gain back all the weight and even more. 

With all this going around, it is fair to say that eating in moderation is the best. Why? Because it one easy to sustain in the long term.

There are no health complications. You just have to eat healthily, sleep right, and exercise right.

How does losing belly fat improve mental wellness?

Research shows that physical self-esteem builds on people’s views of their physical bodies including body image.

The constant feeling we have when walking around with extra loads tied around our waists doesn’t improve our outlook on life.

Poor body image also leads to stigmatization which isolates us from contributing to our society.

For women especially, the bodily changes strongly impact personality and confidence. 

One study found a direct relationship between body esteem and self-esteem in middle-aged women. 

But here’s the good news:

You can get rid of belly fat. And in this article, we will discuss ways for you to lose belly fat and stay healthy and confident.


Here’s the thing: there are no shortcuts if you’re looking to get lean around your midsection.

As we age, our biologies and metabolism slow down. But with simple lifestyle changes and habits, we can lose unwanted fat.

Checking your weight will no longer be a dread. It’ll be something to look forward to.