Your ultimate science-based guide to using CLA (Conjugated Linoleic Acid) for weight loss

Written by , Published: , Updated: July 07, 2017

Hey, and welcome to my science-based guide to using CLA for weight loss.

As you'll see, plenty of research has already been done on CLA.

CLA (Conjugated Linoleic Acid): Your science-based guide

Before we dive in, take a quick look at what you can expect to learn from this guide:

What is CLA (Conjugated Linoleic Acid) and how you can benefit from it

Conjugated Linoleic Acid, or just CLA for short, a healthy kind of "good" fat that helps your body increase metabolic rates. In other words, it helps your body convert food into energy more efficiently. It also boosts your immune system and keeps your cholesterol at normal levels.

Besides its many health benefits, CLA is one of the most popular weight loss supplement on the market.

(If you're interested, you can read my article in which I use modern science to expose fake CLA supplement reviews.)

Why is CLA so popular? Several studies showed that CLA speeds up fat burn and helps build muscles.

CLA is an essential fat, meaning your body can't produce it, but you can find it in some foods and dietary supplements.

So let's take a look at one of the biggest issues you could run into when taking CLA.

The #1 health problem you could run into with CLA

Science proved that CLA from animal sources helps prevent cancer, reduce body fat and build muscles. CLA supplements are also presented as the magical weight loss pills that can help you achieve that lean body you desire so much.

But what most people don't know is that there are at least 28 different forms of CLA. The problem is, they can have a completely different effect on your body.

For example, taking CLA pills could boost your odds of developing fatty liver disease[1]. But on the other hand, eating CLA-rich foods could actually help prevent cancer[2].

This is the most important difference between CLA-rich foods and CLA supplements that weight loss industry "forgets" to mention.

Here’s why...

Products like pills or syrups containing CLA are still unlikely to do you much good because these lab-made CLA supplements aren’t made from animal foods. Look at the labels and you will see that CLA supplements are made from unhealthy vegetable oils .

That’s the reason why you can’t expect to benefit from taking CLA supplements. So keep this in mind BEFORE you decide to buy a CLA supplement.

The healthiest sources of CLA on the planet

Scientists found out that best sources of natural CLA can be found in milk, cheese, and meats. The richest CLA meat is beef, but it is also found in lamb and veal and in pork, chicken, and turkey. Dairy with the richest content of CLA is butter.

You can see how much CLA can be found in natural foods in next table[3]:

MeatsCLA (mg/g fat)
Fresh ground beef4.3
Beef round2.9
Beef frank3.3
Beef smoked sausage3.8
PoultryCLA (mg/g fat)
Fresh ground turkey2.5
SeafoodCLA (mg/g fat)
Lake trout0.5
Dairy ProductsCLA (mg/g fat)
Homogenized milk5.5
Sour cream4.6
Plain yogurt4.8
Ice cream3.6
Sharp cheddar cheese3.6
Mozzarella cheese4.9
Colby cheese6.1
Cottage cheese4.5
Reduced fat swiss6.7
Am. Processed cheese5.0
Cheez whiz5.0
Vegetable OilsCLA (mg/g fat)
Safflower Oil0.7

This is why you can't get enough CLA from most foods

If you eat a "nutritionally complete" diet, you'll get enough CLA to cover your body's needs for it.

But if you wanted to enjoy the extra health benefits of CLA , some studies have shown that you need to get in at least 1.5 g of CLA per day.

In America, the average intake is only about 0.15 g per day for women and 0.21 g for men[4], which is obviously too little CLA.

The problem many people don’t get enough CLA from food is because their meals are mostly made up of boxed, frozen and fast foods.

TIP: Eat more natural, unprocessed (never frozen) CLA-rich foods.

What can you do to get more CLA from food?

To get sufficient CLA from food you would have to eat a lot of fat, which may be a problem for you. So, even if you ate lots of fatty CLA-rich foods, it would still be hard for you to get in even 1 g of CLA a day.

As you can see, the best sources of CLA are very fattening. For example, to eat 1.5 g of CLA, you'd have to eat around 300 g of butter or as much as 1 kg of cheese.

Despite the fact that you may enjoy eating cheese, it’s safe to say you don't like it enough to eat a kilo of cheese a day.

That's the reason why weight loss and health industry started producing CLA supplements with higher amounts of CLA content for people to get the right doses for health benefits and weight loss.

How to reduce the number of calories in CLA-rich foods

Content of CLA in foods depends on the season of the year, what the animals were fed with and the animal’s age.

Grass is rich in linoleic acid and the special enzymes in animals’ digestive systems convert linoleic acid to CLA.

Because of this, milk from grass fed cows can have as much as 500% more CLA than milk from grain fed cows.

TIP: Free-range meats are healthier than other kinds of meats. Ask your local butcher for beef that has come from grass-fed livestock or look at the labels if you're buying meat at your local supermarket. Whenever you can, choose grass-fed meat over grain-fed meat.

Can you take CLA to get rid of that stubborn body fat?

If you're interested in taking CLA to speed up your fat burn rate, you'll be glad to know that a lot of research has already been done on this subject.

At first, several animal studies confirmed CLA can be effective for weight loss. Naturally, this grabbed the interest of many scientists in the field of weight loss.

As a result, we now have more than 30 human studies and we understand the specific conditions under which CLA can actually help you burn off that embarrassing body fat.

But here, you'll see the science that'll tell you exactly how to maximize the weight loss benefits of CLA.

What's the most weight CLA can help you lose?

In one study[1] on CLA and weight loss, people took a CLA supplement for 12 weeks and lost 3 lbs (1.7 kg) of pure body fat.

The strange thing about these weight loss results was, the people in the study didn't actually lose much weight. They lost some of their body fat while they gained a couple of pounds of muscle mass (which is still an awesome benefit).

This happened because the people in the study also followed an intense exercise program (or they wouldn't be able to grow any muscle).

So let's take a look at whether or not CLA still works for weight loss even with people who don't exercise at all.

CLA only works for weight loss if you do this

In another study [2], two groups of people took a CLA supplement for 12 weeks.

The first group was doing 90 minutes of intense exercise three times per week, but the second group only did some light workouts.

The study showed that intense-exercise group lost some extra body fat with CLA, but for the light-exercise group, CLA couldn't help the people lose any extra body fat.

So it looks like CLA can only help you burn off some extra body fat if you're prepared to exercise pretty hard while taking it (think 90-minute, intense workouts at least three times per week).

CLA does NOT work for all overweight people

In one study[3], obese people with a Body Mass Index (BMI) higher than 25 took a CLA supplement for 8 weeks.

On top of taking CLA, the people in the study exercised 3 times per week. A combination of exercise and CLA should help speed up their fat burn rate (as proven by the studies I've shown you so far).

But sadly, the study showed that CLA couldn't help obese people burn off any extra body fat.

The bottom line is, if you still have a lot of weight to lose, then CLA may not help you get rid of that embarrassing body fat any faster (even if you combine it with exercise).

But there's one more benefit of taking CLA for weight loss you should know about. That's the potential to bring down your appetite, hunger, and cravings.

Can CLA help bring down your hunger and appetite?

By far the most common reason why people struggle (and ultimately fail) on most weight loss diets is the fact that those diets skyrocket their hunger and cravings.

This happens because a poorly designed weight loss diet will increase the production of the hunger boosting hormone, leptin.

But what does the hormone that's capable of triggering overwhelming hunger and cravings have to do with CLA?

Well, one weight loss study[4] proved that taking a CLA supplement can bring down the levels of leptin in your body.

In theory, lower levels of leptin in your body should bring down the hunger and cravings (which should help you eat less food and lose more weight).

But the problem is, lower levels of leptin caused by the CLA supplement didn't help the people in the study lose any more weight.

Now I'll go over what should be a top concern for anyone interested in taking any supplement, its side effects.

Also, if you have any health issues or medical conditions, you need to discuss taking CLA (or any other supplement) with your own doctor.

A real life example of CLA side effects

The reason why I even started looking into the side effects of CLA was because one of my clients ran into some trouble when taking it.

She was trying to get rid of some extra body fat and she got a few different supplements that she believed could help her speed up fat loss.

Taking a couple different "fat burners" at once may (or may not) speed up fat loss, but you'll also be exposed to the risk of side effects of ALL the supplements.

Anyways, after three days of taking a CLA supplement she found out that she gets stomach pain within a few minutes of taking a CLA pill.

I told her to stop taking CLA until I do some research and this is what brought this science-based guide to CLA side effects to life.

Diabetics should NEVER use CLA supplements

Studies on animals have shown that CLA can work for fat loss, but at the same time the liver fat increased. This may worsen blood sugar control and worsen insulin resistance in people struggling with diabetes.

Researchers from the Centre for Synthesis and Chemical Biology (CSCB) found out that the form of CLA the weight loss industry is using in CLA pills could throw you into a diabetic state. The natural form of CLA on the other hand had beneficial effects.

Scientists from Trinity Centre for Health Sciences and St. James also discovered that the patients who were taking CLA supplements got higher glucose levels and their insulin sensitivity was lower compared to the placebo group.

TIP: Get a blood test to check your blood sugar levels before taking CLA supplements. If you are pre-diabetic or diabetic, then avoid using CLA supplements.

Let's take a look on one more thing. How CLA affects the cholesterol and triglycerides levels in your blood.

In which case should you talk to your physician before taking CLA?

The problem with knowing how CLA supplements affect your cholesterol levels is that different studies have shown different results (like in this example).

In other words, not all scientists agree about the connection between CLA supplements and cholesterol. Some studies has shown that CLA supplements reduce the "good" cholesterol[3], while others showed the increase in the healthy cholesterol levels.

The reason why we studies have shown different results might be the difference in the quality of different CLA supplements. But I can't be sure of this, because some other differences between groups of people who were tested in the studies.

TIP: Talk to your doctor and check your cholesterol levels before taking any CLA supplements.

Another crazy side effect of CLA

CLA supplements can cause you to bleed out of your nose and can slow down the healing of your wounds. If you're struggling with a bleeding disorders you should be extra careful with CLA. Not that this can also be a problem with healthy people.

Another reason why you may have problems with taking CLA supplements is if you take it with herbs that increase the risk of bleeding. Ginkgo biloba, garlic and saw palmetto are just some examples of this[6].

TIP: CLA can cause extra bleeding during and after surgery. If you have a scheduled surgery, stop taking CLA supplements at least 2 weeks before going to a surgery.

On to how CLA effects kids and pregnant or breastfeeding women.

Is taking a CLA supplement safe during pregnancy?

During pregnancy, many woman are afraid to put on too much weight. Some women turn to weight loss products even as they're still pregnant or breastfeeding. CLA is not necessary for a healthy pregnancy, so I can't really recommend it for pregnant women.

However, we can’t say for sure that a CLA supplement will hurt the unborn or breastfeeding baby, because no studies have looked at the CLA effects on pregnancy yet. The reason we don’t have this information is simple. Women aren't exactly to test the negative effects of any supplement on themselves or their babies.

Just as a general precaution, it’s probably safer to stick to the natural sources of CLA. The same advice goes to breastfeeding mothers and kids.

TIP: If you are thinking about taking a CLA supplement during or after pregnancy, be sure to talk to your doctor about any possible risks.

A few more side effects of CLA

Let's take a look at a couple more known side effects of CLA.

When you first start taking a CLA supplement you may start feeling tired or exhausted. Sometimes it takes a couple of days before you get your energy back.

You may also have diarrhea, pain and cramping in your stomach or become bloated. Keep in mind that diarrhea will dehydrate you, you may fell dizzy and even develop a headache.

TIP: If you do get struck with diarrhea, make sure to drink lots of water.

Other side effects you may get from CLA include sickness and loss of appetite. If you don’t feel normal after a couple of days, it's probably time to stop taking CLA.

An extreme case of side effects after taking a CLA supplement

In one medical case, doctors connected quite a few serious health risks and side effects with taking a CLA supplement.

A 46-year old healthy woman started taking a CLA supplement because she wanted to get rid of her body fat. After 14 days she had symptoms of asthenia, nausea, anorexia, jaundice, and pruritus.

The biopsy of her liver showed she also developed hepatoxicity. Soon after she stopped taking CLA, the levels of enzymes in her liver returned to normal [1].

If you notice any of the above discussed side effects when taking a CLA supplement, you should stop taking CLA immediately and go to your doctor for help/advice.

Actionable takeaways

As you saw, not all CLA is created equal. According to science, you'd do best to avoid CLA in supplement form and stick with CLA-rich foods.

With the richest source of CLA being meats and dairy, it's tough to get in enough CLA without also getting in too many calories.

If you want to up your CLA intake with natural foods (but without having to eat too many calories), you should stick with grass-fed meats.

Because research has shown, that grass-fed meat can have as much as 5 times more CLA than grain-fed meats.

All in all, CLA can help you lose some weight, but only under some pretty specific conditions.

If you're a reasonably fit individual who does not have a lot of weight to lose (and are prepared to commit to a serious exercise program), then CLA will be able to help you out.

David Brown

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