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Weight Loss Vs Fat Loss 101

Did you know good nutrition and healthy eating habits are fundamental in Human Development, Weight Regulation and the Prevention of Chronic Illness?

In today's society, the primary motivator on getting 'Fit' more than often involves losing a certain amount of weight. A lot of this emphasis tends to shift to become more of an external and visual focus rather than internal Health.

As a result, most diets today are started due to poor body image rather than wanting to be within a healthy a healthy weight range.[1]

According to research individuals will at some point believe they are either overweight and begin their obsession in losing weight or, believe they are not muscular enough and begin their obsession about putting on size.[2]

Thus we can categorize individuals whom are generally looking to either:

a) Lose Weight


b) Gain Weight

In the ongoing pursuit of changing our body composition permanently, it's important to understand the varying biological mechanisms that typically take place. But first, lets dive in and define these mechanisms a little further...

What is Weight Loss?

The prime focus of Weight Loss is using one's stored Energy to reach a desired Weight range. Weight loss otherwise known as forced starvation, typically involves using stored energy as fuel rather than a traditional calorie deficit for fat loss.

Weight loss also involves the breakdown of both LBM (Lean Body Mass) to achieve a desired outcome. This typically involves the breakdown of:

- Muscle

- Water

- Fat

- tissue etc.

How to Lose Weight?

Whilst I generally don't recommend 'fad' diets or 'quick' fixes, we can experiment with this in a non-intrusive and non-detrimental way.

So, are you like many others looking to drop some of the weight overnight? Try this simple hack: ⬇️

1. The Day Prior

- consume all your regular meals i.e. breakfast, lunch and dinner

*optional: for the took-hardy folk, elevenses, luncheon, afternoon tea, dinner, supper...

- ensure you drink 2-3 liters of water

- weigh yourself fully clothed (inc shoes) before bed

2. The Day After

- weigh yourself first thing in the morning, post bathroom visit, no clothes (nude).

Congratulations! You've successfully achieved 💯 instant weight loss and lost x amount of kilos without needing to diet!

Is Weight Loss Optimal?

This can depend on context as though the exact mechanisms of body weight regulation in weight loss are unknown, we do have a lot more information available to help us determine if it's optimal.

There is also more evidence now of vigorously losing weight vs effectively losing weight permanently for a particular body weight.

Rapid forced body weight gains and losses of up to 25% have been shown to be quickly reversed when the forced starvation or forced feeding is ended.[3]

Figure 1. Weight Loss vs Weight Regain over time. Within 1 year of Weight lost, 80% relapse to their pre-diet weight. At 2 years it's 85%, at 3 years 95% [9].

Weight loss has also been shown in numerous studies to slow down the Metabolism in the process when calories are restricted. *More on this later...

To quote the National Institutes of Health Technology Assessment Conference Panel:

“Weight regain is generally the rule, with long-term follow up studies indicating that one-third to two-thirds of the weight lost is regained within 1 year and almost all is regained within 4-5 years.”

Whether or not Weight loss is conventional or non can be dependent on the methods applied and how they're applied. This also appears to have a strong influence on the overall determinant of successful weight loss.[4]

Weight Loss Summary

- The way in which you diet matters...

- The amount of time you spend dieting matters...

- How quickly you regain the weight matters...

Granted there is no right or wrong way to Lose Weight. However there is evidence to help us determine non-optimal ways vs optimal ways of permanently changing one's body composition for good...

Let's keep going.

What is Fat Loss?

in short, Fat Loss is the rate of burning Body fat over time. It also initially involves speeding up or 'boosting' your Metabolism to successfully change your body composition over time.

Fat Loss requires one to be in a Caloric Deficit for the process to occur. It also involves the breakdown of Fat rather than LBM (Lean Body Mass) when a conservative approach is followed.

This is important as LBM helps increase your BMR/RMR, also allowing you to eat more Calories.[5] *More on this later.

Unlike Weight Loss however, Fat loss isn't always linear. Furthermore results aren't generally instant and occur overnight as the fat loss mechanism(s) takes place over time:

Figure 2. Tracking Weight Loss progress using MyFitnessPal.

Difference between Weight Loss vs Fat loss?

In some cases, there may be still be a requirement to drop a significant amount of weight for any given day in particular a sport or task:

i.e. boxer looking to cut weight for their weigh-in or powerlifter looking to drop weight for a meet.

There are some individuals whom are initially successful at losing weight i.e. post-partum females but are also unsuccessful at keeping the weight off long term. *More on this later. Whilst these individuals may not require a specific aesthetic or conditioned look, there are some sports which largely require you to do so:

i.e. bodybuilder or physique athlete looking to place in their division. Beauty pageant, sports model etc.

With the varying differences of changing body composition pre-deposition, there is one key element missing...


Figure 3. Visual progress of Weight Loss vs Fat Loss

The above helps illustrate the visual difference between Weight loss (Significant loss of LBM) and Fat loss (Little to no loss of LBM). During Weight loss, Lean muscle mass, bone density, and body fat all appear to be maintained within a relatively narrow range. This is accomplished by a constant balance of anabolism and catabolism (building up and breaking down).[7,8]

Whilst Weight loss significantly influences a greater degree of weight loss on the scale through loss of LBM and total weight loss, it also has little to no affect on changing overall body composition. Fat loss however tends to inhibit a more positive affect on changing overall body composition whilst keeping most if not all of LBM intact when following an energy balanced diet.[6]


It can be important to know the difference between the two when undertaking any Fitness regime or Diet program. Context is also important.

If you've been training for an event with specific weight entry requirements and have mistimed it, weight loss may help you just get by.

If you've been lifting weights for some time and looking to be more 'toned', you will benefit more from Fat loss.


Join us next time as we start to delve deeper into the mechanisms behind Fat Loss from both a physiological and biological standpoint.


If you're interested in knowing more on these concepts of Fat Loss or Weight Loss, they are also covered in my Nutrition eBook 'Eating for a Purpose - Basic Concepts on Nutritional Value' available now.


1,2,5,6. Cruz, Franz - Eating for a Purpose: Basic Concepts on Nutritional Value (2015) - Process of Elimination, Body Image issues, page 18 & 19; Energy Consumption, The Calorie (Thermodynamic) model, page 10; Process of Elimination, Bodyfat for Females, page 21.

3. Sims, E.A.H., and Horton, E.S. : Endocrine and Metabolic adaptation to obesity and starvation. Amer. J. Clin. Nutr.,21:1455-1470, 1968.

4. Keys, A., Brozek, J., Henschel, A. Et. al. (1950). The Biology of Human Starvation. University of Minnesota Press,Minneapolis.

7. Keesey, Richard E. (1980). "A Set-Point Analysis of the Regulation of Body Weight," in Stunkard, Albert J., Obesity. W.B. Saunders Co. 8. "Engelberg, J. : Physiological regulation : The steady state. The Physiologist, 9:69-88,1966"

9. Am J Physiol Regul Integr Comp Physiol. 2011 Sep;301(3):R581-600. doi: 10.1152/ajpregu.00755.2010. Epub 2011 Jun 15. Biology's response to dieting: the impetus for weight regain.

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