Why is body composition important to understand?

At first glance, the term ‘skinny fat’ might appear to make little sense. After all, the two words are totally at odds with one another. However, the term is used widely to describe someone who seems slim but is actually storing a high amount of body fat. 

Their weight is considered in the healthy range according to their body mass index, although their body composition tells a very different story. 

This is why appearance and body weight alone aren’t reliable indicators of a reasonable body fat percentage. Instead, it’s crucial to understand your body composition to work out whether you’re carrying an ideal amount of internal body fat. Here’s everything you need to know about the skinny-fat body type and why body composition is fundamental to healthy weight loss.

What does a 'skinny fat' body type mean?

A skinny fat body type is one that looks lean from the outside but has high body fat and low muscle mass on the inside. Skinny fat people may have a ‘normal’ body mass index (BMI), however, this isn’t always a sound way of gauging healthy fat levels. 

BMI looks at weight and height, not your overall body composition — so things like body fat percentage, muscle mass and skeletal mass. Instead, some consider lean body mass (your overall weight minus your body fat weight) to be a better measure of health. 

Note that ‘skinny fat’ is not an official medical term. However, it’s used pretty frequently in fitness and nutrition to describe this particular body type. 

You might also hear it referred to as ‘metabolically obese normal weight’ (MONW), which is where someone is in the normal weight range but has the markers of obesity like too much fat, impaired insulin sensitivity, and a higher likelihood of diabetes, cardiovascular disease and death [1].

How do you measure body fat percentage?

Measuring body fat percentage can really help you understand your body composition better, especially if you’re aiming to make some changes. There are a few popular methods out there that cater to different preferences and budgets. For starters, skinfold callipers are a classic choice; they involve pinching the skin and measuring body fat in certain areas. If you want something a bit more high-tech, bioelectrical impedance scales use a tiny electrical current to calculate body fat percentage based on how easily it moves through your body.

For those who are looking for even more accuracy, hydrostatic weighing, or underwater weighing, measures how much you weigh on land versus in water to calculate body fat. Then there’s Dual-Energy X-ray Absorptiometry (DEXA), which uses X-ray technology to break down your body composition into fat, lean tissue, and bone. And if you're after a more modern approach, 3D body scanners can provide a detailed view of your body composition in a flash.

Keep in mind that each method has its pros and cons, and factors like hydration can affect results. If you're serious about tracking your body fat percentage, consider combining a couple of these methods or consulting a professional for the most accurate insights.

What are the signs of a 'skinny fat' body?

There are a few tell-tale signs when it comes to being skinny fat [2]. Someone might appear to be slim and reveal a healthy weight on the scales, but their body could be hiding any or all of the following:

• Excess fat around the belly— for women, a waist measurement greater than 80cm (31 inches) increases the risk of chronic disease [3]. Many women, especially those going through menopause, struggle with excess belly fat.
• Sometimes, extra fat on the backs of the arms
• Low muscle mass and definition.

Other things that can indicate a skinny fat body include eating a poor diet and not putting on weight, and not doing enough exercise. Someone who’s skinny fat may also feel exhausted or out of breath after only a brief amount of exercise.

Why do people gain fat and lose muscle?

Interestingly, high body fat percentage and low muscle mass are heavily intertwined. This is because weight gain and muscle loss tend to happen concurrently [4]. 

A lot of the time, this is due to age-related muscle loss and a reduction in metabolic rate. In other words, you lose muscle, and your metabolism naturally slows down as you get older. These factors mean your body can have a higher fat percentage and lower muscle mass over time. 

Other things can exacerbate this change in body composition, including losing weight purely through diet. In a healthy weight loss program, your body should use fat for energy before muscle. But if you’re not eating, heavily restricting calories, cutting a particular food group or staying in a calorie deficit for too long, the opposite can happen. 

The same goes if you don’t incorporate any resistance training (also known as weight training or strength training) into your exercise routine. But more on this shortly.

What causes someone to become 'skinny fat'?

There are several reasons why someone might become skinny fat, from lifestyle to genetic factors.

Genetic predisposition

Unfortunately, biology plays a large part in determining body composition. How much fat your body retains and where your body stores fat are largely determined by genes [5]. So, if you have an immediate family member with a skinny-fat body type, there’s a higher chance you’ll have one too.

Lifestyle habits

Someone who’s skinny fat will often have a diet high in processed foods, sugar and refined carbohydrates, but low in whole foods, fibre and protein. On top of that, they may not be doing enough — or any — exercise. Alternatively, they might be focusing only on cardio and avoiding weight-bearing exercises. Only doing cardio can contribute to muscle loss [4]. On the other hand, resistance training is essential for muscle growth.

Hormonal imbalance

In some cases, hormonal imbalances can lead to excess fat, particularly around the midsection. The different hormonal imbalances and conditions linked with belly fat include low estrogen (often a result of menopause), hypothyroidism (an underactive thyroid), insulin resistance, elevated cortisol (due to ongoing stress) and leptin imbalance.

Prolonged calorie deficit

A calorie deficit is when you use more energy than you consume, which is the basic premise of weight loss. But if you stay in a state of calorie deficit for a long time — that is, beyond reaching your target body weight — your body can actually start to eat away at your muscles [6]. 

As a result, your body may store more fat and less muscle, leading to a skinny-fat physique.

Are there any dangers of being 'skinny fat'?

Unfortunately, anyone with excess body fat — particularly around their mid-section — is at risk of certain health issues. Your body contains 2 types of fat: subcutaneous fat (the fat you can see and feel) and visceral fat. Often, those with a skinny fat body carry a high amount of visceral fat — i.e. the kind you definitely don’t want. 

Visceral fat is hidden fat that sits around the belly, surrounding your organs. It's one of the main signs of metabolic syndrome, a term used to describe disorders like obesity, high blood pressure, high cholesterol and insulin resistance. 

Metabolic syndrome also raises your risk of cardiovascular problems, stroke and type 2 diabetes [3]. 

Excess visceral fat is linked to other conditions too, including breast and other types of cancer, liver disease, dementia, fertility issues and osteoarthritis [7].

Who’s at risk of being ‘skinny fat’?

The people most at risk of having an unhealthy body fat percentage, or MONW, are those who are lean but have the metabolic profile of someone who’s overweight. Several things make a person predisposed to becoming skinny fat, including:

• Maintaining an unhealthy diet
• Doing a low amount of (or no) physical activity, particularly weight training
• Having impaired insulin sensitivity
• Having high blood pressure
• Having high triglyceride levels (this is a type of fat found in the blood)
• Having high LDL cholesterol and/or low HDL cholesterol (in other words, too much of the ‘bad’ type and not enough of the ‘good’ type)
• Having immediate family members with a skinny-fat body type.

How to overcome being 'skinny fat'

Even if your body is showing the signs of being skinny fat, you can definitely turn things around and work towards a healthy body fat percentage. Here’s how to reduce body fat and build and maintain muscle the right way.

Add weight training to your routine

The benefits of aerobic exercise, or cardio, for your overall health can’t be underestimated. It reduces the risk of heart disease, offers mental health benefits, and can help manage other conditions, including diabetes [8]. 

However, if your exercise routine only contains cardio, you may not be doing enough to build muscle and maintain adequate muscle mass. It's important to combine cardio and strength training to achieve fat loss and muscle gain.

Not only will this build muscle in your body needed to overcome a skinny fat body, but it will also improve bone density, the function of your joints and overall strength [10].

You can easily incorporate resistance training into your routine by lifting weights and doing squats, push-ups and any other exercises that put your muscles to work.

Maintain a balanced diet

Eating healthily is another pillar of sustainable weight loss and achieving optimal body fat percentage.

Protein should be a fundamental part of your diet, as it’s needed to build muscle. Animal-based protein sources like meat, eggs and dairy tend to be absorbed better. However, plant-based sources like tofu, legumes, nuts and seeds are still valuable [11].

Ensure you’re eating lots of other nutritious foods too, like whole grains, fruits, vegetables and healthy fats. Wherever possible, limit processed foods, sugary drinks and anything high in salt and saturated fat [12].

Lose body fat slowly

Healthy, sustained weight loss isn’t about skipping meals, cutting out a particular food group or reducing energy intake to a dangerously low level. 

Experts generally agree that a weight loss rate of about 1-2 pounds per week is safest [13]. Anything that promises drastic results in a short period of time can have negative consequences on your body, including muscle depletion, rapid weight gain following the initial loss, and a slowing of your metabolism [14].

To lose body fat safely, aim for 30 minutes of exercise on most days combined with a reduction in energy intake of 500 calories. And unless you’ve got direction from a healthcare professional, your energy intake shouldn’t drop below 1200 calories per day if you’re a woman [13].

Address any underlying issues

If you think you're trying to achieve a healthy body fat percentage, diet and exercise are not the only issues you might need to address. Some skinny-fat bodies might be due to a hormonal imbalance. If you think this could be the case for you, make an appointment with a healthcare professional to address it. Your doctor can check for conditions like hypothyroidism, liver problems, chronic stress and estrogen imbalance by looking at your hormone levels.

Tackling these through medication and other treatments, like hormone replacement therapy, may contribute to combating a skinny-fat body.

Consider extra support to lose weight

Sometimes, it helps to have dedicated resources and support throughout your weight loss journey.

At Juniper, we combine weight loss medications with dietitian-led health coaching and tracking, so you can lose weight and reach your goals for good. 

Kickstart your weight loss journey with Mounjaro, Ozempic, Wegovy or Zepbound. These groundbreaking weight loss medications mimic the GLP-1 and GIP hormones, respectively, to help control cravings, delay stomach emptying, and keep you feeling fuller for longer. 

Plus, we have a team of expert dietitians and health coaches you can consult with to help you work through any challenges you're experiencing during your weight management journey. This approach sets you up for sustained weight loss, rather than a quick-fix solution.

This means you can continue to enjoy the things you love in moderation without ever feeling deprived.

Ready to see if Juniper is right for you? You can check your eligibility here. 

Is body recomposition the right solution to lose fat?

Body recomposition, where you aim to lose body fat and gain muscle, is a great option for sustained, safe and long-term weight loss. Building muscle supports metabolic function, overall strength, improved bone density and more. 

However, achieving good body composition does require a lot of dedication and the right balance of exercises and dietary changes. This is why engaging a healthcare or weight loss professional to help you lose weight can be beneficial. They can ensure you’re achieving your weight loss goals and help clients improve body composition in a sustainable and healthy way.

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