Fat Cells: The Real Reason For Unwanted Weight Gain AND The Microscopic Key to Weight Loss Success!

Our bodies are made of cells. Muscle cells make up muscles, brain cells make up our brain, and bone cells make up bones. But for some reason, when it comes to body fat, the cells making up that fat (adipocytes) are rarely discussed or acknowledged. The fact is, without abnormal fat cells, unwanted weight gain cannot occur! Let me explain….

Imagine if something triggered your muscle cells to suddenly enlarge and multiply to the point that your muscles doubled, tripled, and then quadrupled in size! For most people, the added bulk would be a major bother. What if our skin cells started enlarging and multiplying to the point that our skin became baggy and was dragging around on the floor as we walked. How bizarre!

Although those examples seem strange to consider, the fact is, when people develop unwanted body fat, including true obesity, that exact type of tissue enlargement is taking place within fat tissue. And, in America, many people unfortunately seem to accept this disease process as “normal”, common, and typical.

This process, as I’ve described it, is taking place among the fat cells, scientifically known as “adipocytes”. If you are struggling with unwanted weight gain, control at the level of the fat cell is crucial for success. After all, the fat cell is ultimately where the battle is occurring. To understand the successful management of unwanted weight gain, I believe you should understand the following two ABNORMAL phases of fat cells that frequently occur. And if you are the victim of unwanted body fat, these have, in fact, already occurred inside your body! If so, it is crucial that you read further and understand the two MANAGEMENT phases of fat cells that must occur to achieve an optimum weight.

Consider these 2 PHASES OF FAT CELL GROWTH that you likely have never heard:

FAT CELL GROWTH PHASE #1: Fat cells increase in size.

We are born with a certain number of normal fat cells inside our body. Those fat cells serve a very important purpose. In times of “plenty”, they are able to store a limited number of extra calories in reserve for times of famine. Then, when needed, they can be called upon to deliver the saved up fat calories as a source of energy.

This ability of fat cells to store extra calories is based on their amazing ability to be flexible in their size and storage capacity. Think about a rubber balloon. The balloon can hold a little air or a lot of air, depending on how much air is pushed inside the balloon. Fat cells are the same way. Depending on how many molecules of fat are transported into the cell, they will vary in size.

Fat Cell

This photo is an electron microscope view of healthy fat cells. Note: Fat cells are extremely small. 5 fat cells will fit on the end of the lead of an ever-sharp pencil tip.

Fat cells, in most healthy adults, contain, on average, 66 mcg of fat (not very much, but there are billions of them!). These fat cells can fluctuate up or down in size, from around 20 mcg to 100 mcg. To put it simply, fat cells can vary from 20% full up to 100% full capacity. Normal would, on average, be around 66% (2/3) full.

Phase I of obesity occurs when some or all of your fat cells increase from 66% capacity towards 100% capacity. Since adults normally have 30 lbs or so of body fat and the existing fat cells can increase their storage capacity by only 50%, this increase in cell size can increase body fat by no more than 15 lbs, a 50% increase. (Note: For simplicity, I am using average, approximate cell sizes. Cells among individuals vary in size, but the concepts and phases are always the same. The crucial point here is that each of your fat cells have limited storage capacity.)

Next, if even a fraction of your fat cells are forced to expand beyond capacity, the unwanted Phase #2 of obesity MUST occur!

FAT CELL GROWTH PHASE #2: Fat cells increase in number.

We are born with around 5 billion fat cells. Some of us are born with more than others. Most healthy adults, however, end up with around 25-30 billion fat cells by early adulthood. It is normal for fat cells to increase to an adult number, increasing from 5 billion at birth to 25-30 billion. These fat cells typically increase in number primarily during certain times of life:

  • the first 2 years of life
  • adolescence (ages 9-13)
  • during excessive or rapid weight gain
  • during excessive weight gain while pregnant (i.e. gaining > 28 lbs)

It is crucial to control nutrition and body weight throughout life to prevent fat cells from multiplying. One research study documented a 2.6 billion fat cell increase in just 8 weeks of overeating, a 10% increase of fat cells in 2 months!

Fat cell multiplication occurs when current fat cells have reached their capacity to hold fat and they “call out” for help. The process is driven by hormone signals. The fat cells actually send signals to primitive stem cells known as “pre-adipocytes” telling them to become fat storage cells known as adipocytes (fat cells).

Fat cells increase their number when more cells are needed to store extra, unnecessary calories that are entering the body.

When fat cells multiply, the number of fat cells can increase from the normal 30 billion to 90+ billion. One research participant who had become obese very early in life was found to have 160 billion fat cells, more than 5 times the normal number!

To summarize, fat cells, in Phase I, increase in size up to 50% (adding 15 lbs of body fat). In Phase II, they can more than triple in number (adding 60-100 lbs or more of body fat!).

Now, consider these 2 PHASES OF WEIGHT LOSS through FAT CELL CONTROL:

WEIGHT LOSS PHASE #1: Fat cells decrease in size.

Let’s start with the example of an individual gaining 15 lbs by simply expanding the size of his/her fat cells. That initial 15 lbs of weight gain is managed by decreasing the size of the fat cells by using those calories as fuel. Fat cells then return to their original, normal size and normal weight is again achieved.
This 15 lb fluctuation, up or down from one’s normal weight is not a disease. It can even be seasonal and normal. It is how our body’s fat cells are designed to function. (Note: Unfortunately, in some individuals, even 10 lbs of rapid weight gain from high sugar has been shown to increase fat cell number by 10% (2.6 billion!), so if you gain 15 lbs, let it be over months or years, not over a few weeks of binge eating on sugar!)

Weight loss is characterized by a simple decrease in the size of your fat cells. In fact, research studies have proven time and again that as people lose weight, their fat cells can and do shrink in size and fat content. This is great news! We have a method for control!

Remember, fat cells be anywhere from 20% to 100% filled with fat. If you are overweight, you must force your fat cells to be on the smaller side! Depending on how much weight you have gained, you may need to reduce and maintain your fat cells at 30-100% of their original “pre-weight gain” normal size.

WEIGHT LOSS PHASE #2: Fat cells MUST be kept “small” long term.

Since fat cells can both decrease or increase in size, once you begin shrinking your fat cells, you must persevere. If you do not maintain control of the fat cells, they will inevitably resume their function of storing more fat and again increase in size (and in number if you exceed your prior “heaviest ever” weight!). Whenever fat cell enlargement happens, unwanted weight regain is the result.

Maintaining control of your fat cells is both simple and complex. It is simple in theory, but complex in implementation. The main error people make when it comes to managing overweight problems is to underestimate the difficulty of fat cell control long term. Appetite factors, a sluggish metabolism, and nutritional intake must all be managed long term to stay in control. Although difficult if not managed appropriately, it is VERY achievable, and so very worth it!


Over the years, I have had the privilege of assisting thousands of successful individuals in “managing” their fat cells. I’ve learned that it does not take an exceptional IQ, impossible self-discipline, or painful, inhumane exercise routines. It does require determination, proper goals, a teachable spirit, and effective long-term tools and strategies that are part of a personal treatment plan for this challenging “fat-storage” disease of obesity that we battle.

If you are overweight, embrace the challenge, and allow others to support and assist you on your journey. We would be honored to play a role in your success. Optimum weight and body composition are the mandatory components of Optimum Health, which is always worth the effort.

For Optimum Health,

Rick Tague, M.D., M.P.H.

Rick Tague, M.D., M.P.H. & T.M. is a nutrition & weight loss specialist and the Founder & Medical Director of the Center for Nutrition and Preventive Medicine, P.A.

Dr. Tague is an Alpha Omega Alpha honors graduate of Tulane University School of Medicine in New Orleans. He also holds a Masters Degree in Public Health from Tulane. Dr. Tague is board certified by the American Board of Obesity Medicine and the American Board of Family Medicine. His medical practice has focused on optimum health, nutrition, and weight loss since 1996.

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