Decrease Excess Fat, Build Muscle!
Behold - the holy grail of body composition goals.
As an endocrinologist who specializes in cardiometabolic health, I focus a lot of time on evaluating and targeting the source of what causes certain cardiometabolic medical conditions, such as: obesity, insulin resistance, high blood pressure, pre-diabetes, type 2 diabetes, metabolic dysfunction associated liver disease ( aka MASLD - formerly known as non-alcoholic fatty liver disease), and high cholesterol.
The common source for many of these conditions is the abnormal hormonal signaling that results from accumulation of excess and/or dysfunctional fat mass (also known as adiposopathy, read more about that here). Reducing excess fat mass and treating the fat mass dysfunction is therefore the focus and target of my work with patients to address the root cause of their disease. For many, this involves weight loss.
BUT - I am VERY specific about what weight loss means. I do not give weight targets. I honestly find weight targets to be misleading as they focus the attention on the wrong health measure, which is total weight - the first number a person sees when they step on a scale. This weight is made up of the weight of fat, muscle, water, bone, and more. The specific form of weight loss I focus on and target is excess weight coming from fat mass.
What’s the difference?
If someone loses, say, 30 pounds in a very short amount of time, it is not uncommon that half, or even more than half of that extreme weight loss could be from muscle loss. This is extremely problematic and unhealthy, given the negative consequences muscle loss has on bone density and overall health span. The goal, therefore, is to lose 30 pounds of excess fat (assuming there is at least that much to lose) while maintaining or even building skeletal muscle.
Let me break down further what this means.
Excess Fat Mass
We all need some fat - for insulation, protection of organs, and general energy storage. But health starts to become compromised when we exceed our natural fat stores and when the fat tissue becomes dysfunctional in how it acts. Dysfunctional fat tissue secretes harmful chemicals that cause inflammation and has a direct link to the development of the cardiometabolic conditions I listed above. So how do we determine when fat mass has exceeded what is healthy?
First, we need an accurate body composition machine. Through body composition analysis, one of the measures reported is fat mass percentage, meaning, the percentage of a person’s total weight that is made up of fat. In men, the goal is a fat mass percentage <23% and in women, the fat mass percentage goal is <30%. So, when people are losing weight, this fat mass percentage should also go down. If a person loses weight, but the fat mass percentage goes up, guess what that means? That means that the person lost more muscle than fat and so the amount of weight that is made up of fat has gone up, despite weight loss. This is NOT what we want.
Visceral Adipose Tissue
This is the fat that is deep down in the visceral cavity, the fat that surrounds the intestines, the liver, and the pancreas. A high amount of visceral adipose tissue is a prime example of dysfunctional fat and increases the risk of cardiovascular disease, type 2 diabetes, and MASLD. In men, the goal is to have a visceral adipose tissue volume of less than 2-3L and in women less than 1-1.3L.
If there is no body composition machine, don’t fret. Using waist circumference is an alternative way to measure cardiometabolic risk. The goal in men is to get to a waist circumference less than 40 inches ( or <35.4 inches in Asian men) and less than 35 inches in women (or <31.5 inches in Asian women). As you can see, there are ethnic variations and even more that are important to understand that extend beyond caucasian and Asian.
Note that nowhere above did I mention body mass index, BMI. That is intentional. BMI takes total weight and is unable to separate the components of weight dedicated to fat mass and muscle mass.
Now that it is understood what is meant by excess weight, how then can excess weight loss be targeted and muscle mass maintained?
Doing this requires 3 important factors:
Precision: Here I am referring to a precise way to measure the different components of body composition (fat mass versus skeletal muscle mass) so that the conversation remains focused on the components of weight we need to lose and keep for health. In my office, I use the most accurate bioimpedance analysis machine on the market to make these precise measurements.
Plan: This means an intentional plan on how to modify health behaviors that specifies nutrition targets as well as frequency and types of exercise. More on this below.
Time: Having a plan and precise measures to follow also requires time for execution and time needed to see the intended results. Additionally, taking the time to understand why behavior change is important and how it is improving health helps make these changes sustainable and permanent.
A Plan
Obviously, the specifics of one person’s plan is going to be different from another person's plan. This highlights the importance of personalized medicine and working with a physician with expertise in this area who can customize and outline the specific target measures. However, here are some overarching factors that apply to everyone.
Nutrition
Focus on the quality of the food you eat.
The decisions we make as to how we nourish ourselves has a tremendous impact on health. Shifting the focus on the quality of the food you take in will make breaking unhealthy eating habits easier. Here are things to prioritize:
Prioritize eating whole foods. This means foods in their real form as much as possible, such as eating a whole apple (yes, with the skin) rather than drinking apple juice or apple sauce.
Boost fiber rich foods. This helps promote diversity of the healthy gut bacteria which is important not only for healthy digestion, but also satiety signals (when to stop eating), blood sugar stabilization, as well as the production of short chain fatty acids, which have an anti-inflammatory effect in the body. Lowering inflammation improves health.
Get enough LEAN protein. Yes - protein is very important. Also- the QUALITY of our protein is very important. We do not want to justify eating just any type of protein for the sake of getting enough protein while sacrificing other health measures, like insulin resistance, blood pressure, and cholesterol. I’m looking at you cheese, whole milk, and red meat - all sources of high saturated fat. It is absolutely possible to get in enough lean protein to help support muscle growth while avoiding the high fat protein sources. Some of my favorite lean protein sources include low fat unsweetened Greek yogurt (I use a dairy-free kind), lentils, edamame, tempeh, almonds, walnuts, and protein powder that does not contain added sugars. If you eat animal products, lean sources include zero fat unsweetened Greek yogurt, egg whites, and grilled or baked fish or other white meat.
Exercise
Cardiovascular and strength training are both necessary.
Cardiovascular exercise is part of the movement strategy to target fat mass loss. Knowing what substrate fuels movement at different intensities is helpful when understanding how we can use cardiovascular exercise to aid in excess fat loss. When we exercise, our heart rate increases and the ranges our heart rates fall into during exercise can be subdivided into zones, with zone 1 being the easiest and zone 5 being the most intense. In the lower zones (zones 1 and 2), the energy source that our body uses to fuel movement is fat, whereas in the higher intensity zones (zones 3-5), our body uses glucose. Therefore, ensuring that part of one's weekly movement habit is getting in 120-150 minutes of steady zone 2 exercise is an important part of targeting fat mass loss. While there are precise ways of determining one's individual heart rate zone targets, a simple way to determine yours is by doing this calculation: 220 - your age. Then multiple this number by 0.65 to get an estimate of what your zone 2 heart rate target is.
Strength training aids muscle mass growth. Muscle mass won’t increase just by eating enough protein without actually doing weight training. The reverse is true as well: you cannot build muscle by weight training and then not nourish yourself with enough protein. Both need to exist in order to maintain and build muscle.
With weight training, make sure to target upper body, lower body, and torso strength. The goal is to have to push against, pull upon, or hold onto a heavy weight where we are challenging our muscles (shakes are good!), utilizing our balance, and experiencing muscle fatigue at the end of the rep. Pain is never the goal, but don’t shy away from discomfort. There is a difference between the two.
I hone in on nutritional quality with each patient and we make sure that there is sufficient resistance training happening (which at a minimum, is twice a week), so that the changes in body composition result in reduced % body fat, reduced visceral adipose tissue, all while maintaining or even gaining muscle mass. I am thrilled to have this be the norm for my patients. And this is exhilarating to see as we compare body composition analyses over time and have these new health behaviors solidify into long-term habits.