How To Lose Fat: Belly, Butt, Hips & Thighs
If you want to know how to burn stubborn fat, you have to understand a few key points. I realize many people who read the Metabolic Effect blog are not interested in the science and just want to know what to do. For those types please skip down to the section called “Overview and Action Steps”
First, lets review the fat burning process. In order for fat to be lost from a particular area the following events need to occur
Fat needs to be released from a fat cell (this process of fat breakdown and release is called “lipolysis”).
Fat needs to be carried to another cell through the blood stream (poor blood flow to an area means slow fat loss from an area).
Fat needs to enter another cell to be burned (this process of fat actually being burned is called “lipid oxidation”).
It is important to note here that just because fat is broken down and released (lipolysis), does not automatically mean it will find its way to another cell and ultimately be burned (lipid oxidation). It could be restored and this is often the case in people who are very insulin resistant.
Brief biochemistry overview
To further understand stubborn fat we need to cover some basic biochemistry first. Fat enters or leaves fat cells mainly due to the activity of two enzymes, lipoprotein lipase (LPL) which acts to store fat and hormone sensitive lipase (HSL) which acts to release fat. Notice the name of the major fat releasing enzyme? Is called hormone sensitive lipase and not calorie sensitive lipase for a reason.
IMG_0641HSL releases fat due to signaling of a compound called cyclic AMP. And this is impacted by the activity of hormone receptors in fat tissue called adrenergic receptors (AR).
There are two type of adrenergic receptors. Alpha adrenergic receptors and beta adrenergic receptors. The alpha receptors slow fat release and beta receptors speed fat release. To keep this straight in your head think “A” for “anti-burn” and “B” for “burn”.
In addition to having an impact on fat release directly, these receptors also impact blood flow. More alpha receptors mean less blood flow to an area, and more beta receptors mean greater blood flow to an area.
Hormones & Stubborn fat
So what makes stubborn fat more stubborn? Fat gain or loss is about two things, calories and hormones. But stubborn fat may be more impacted by hormones compared to other types of fat.
Many types of hormones impact fat gain and fat loss. These hormones have this impact because of their direct or indirect effects on the enzymes and receptors we just mentioned. Hormones that store fat tend to increase the number or activity of alpha receptors and/or LPL. Hormones that stimulate fat release increase the number or activity of beta receptors and/or HSL.
Certain hormones have a very straightforward impact on fat gain or loss. For example, Insulin is a fat storing hormone because it increases LPL activity and suppresses HSL activity. Insulin also impairs the normal function of beta receptors, which is another form of HSL inhibition (i.e. insulin lowers HSL activity directly and indirectly via beta receptor disruption).
Catecholamines (adrenaline & noradrenaline to our UK/European friends and epinephrine & norepinephrine to us Americans) speed fat release when they bind beta receptors, which would increase HSL activity. But they can also slow fat release when they bind alpha receptors. This is one of the reasons stubborn fat, which has a higher concentration of alpha receptors, can be so slow to respond.
Other hormones have more complex and overlapping activity. Estrogen seems to both increase the number AND activity of alpha adrenergic receptors. The female fat distribution, where fat is stored in the lower body, is primarily due to the impact of estrogen (the subcutaneous fat and especially the lower body subcutaneous fat of women is richer in estrogen receptors).
Thyroid hormone increases beta receptor activity, blocks the activity of alpha receptors and works in opposition to estrogen making stubborn fat less stubborn. However, thyroid hormone is disrupted itself by estrogen (one of the reasons women have larger thyroid glands compared to men).
Is your head spinning yet? Don’t worry, it will all make sense soon. Here are a few takeaways regarding stubborn fat in general and some hormonal effects to keep in mind.
Stubborn fat has more alpha receptors
Stubborn fat has less beta receptors
Stubborn fat stores more fat and releases less of it under the influence of insulin
Stubborn fat has less blood flow through it
Hormones that increase HSL activity and/or inhibit LPL activity stimulate fat release
Hormones that decrease HSL activity and/or stimulate LPL action encourage fat storage
Calories matter too. It is impossible to store fat regardless of hormonal action in a low calorie state and it is unlikely to lose fat if you are in calorie excess
Stubborn fat is stubborn not because it can’t be released, but rather because it releases fat much more slowly compared to less stubborn fat.
The sex steroids (estrogen, progesterone and testosterone) have receptors in fat tissue and play an important role in HSL/LPL activity as well as impact alpha versus beta receptor number and activity