The Science Behind Fat Loss + The Strategies To Use
If your goal is to lose weight, then more than likely what you’re specifically looking for is fat loss. There are several ways that you can lose weight, but there is only one way that you can lose fat.
In today’s blog post we’re going to simplify & explain more of the science of fat loss, to help you feel more empowered & confident in your journey!
FAT LOSS VS. WEIGHT LOSS: WHAT’S THE DIFFERENCE?
Achieving fat loss means that you’re decreasing the amount of fat that makes up your total body mass. When we step on the scale, there are a couple factors that go into the number that we see.
The first factor is our lean mass. This includes all of the weight from the functional parts of our body: muscle mass, organs, bones, blood/fluid, etc. This is the majority of what makes up our total body mass.
The second factor is the amount of fat mass we hold. This is all of the extra stored energy we have for later use. This should make up much less of your total body mass.
While our weight can fluctuate up and down based on body fat levels; it can also do so based on muscle loss, water loss, blood loss, using the restroom, and so much more.
Oftentimes, we’ll experience weight fluctuations due to loss in water or fluid, and this can mess with our perception of our progress.
This is also where a lot of gimmicks and “quick fixes” come into play. This is where most people fall into a continual loop of losing and regaining weight, after trying gimmick after gimmick.
The problem is that sooo many of these weight loss companies are targeting quick results through water loss, or they are selling a complete placebo. Diet cleanses, juicing, and fat loss gels are a great example of that.
This is why it’s important to understand that the scale is only a tool, and that fat loss is much different than loss in weight itself.
HOW TO ACHIEVE FAT LOSS
The only way to achieve fat loss is through a caloric deficit. A caloric deficit is when your energy output is greater than your energy input.
The equation for fat loss is:
caloric intake < TDEE = caloric deficit
You cannot lose fat in any other way. You can lose water weight and muscle without this equation, but you CANNOT lose fat without a caloric deficit.
You have room for choice in how you want to go about achieving your caloric deficit. You can reduce calories below maintenance, increase your activity levels, or a combination of both. Our personal recommendation is that you opt for both using nutrition and exercise as tools for your fat loss. This means that you don’t have to decrease calories too much nor increase exercise too much. Small changes with both can really help you in feeling better and making faster progress.
Let’s talk CALORIC INTAKE
Before we get into decreasing our caloric intake, we should better understand why we don’t just completely eliminate food, or even drastically decrease calories. The only way we’re able to give ourselves energy is through food and drinks that contain calories. There are four different types of energy sources that provide calories. These are called our macronutrients (macros).
The four macros:
Protein (1 gram = 4 calories)
Carbs (1 gram = 4 calories)
Fats (1 gram = 9 calories)
Alcohol (1 gram = 7 calories)
Other than alcohol, all of the macros serve a functional purpose for keeping our system functional and healthy. The key for healthy fat loss, when nutrition is involved, is to maintain balance between our macros while decreasing our overall intake.
If we cut calories or macro portions too drastically, it can cause a slight upset internally. Our bodies adapt to our diets and routines. This is why changes should generally be made slowly when it comes to calorie reduction, to keep your system in balance.
CALORIC DEFICIT
If you want to use nutrition as your main tool for fat loss, then a calorie deficit is going to be crucial here. As mentioned already, we don’t want to decrease our calories drastically. Aim to decrease your calories anywhere from 100-200 calories.
As your body fat decreases, so will your needs for extra energy (calories). Because of this, every 3-4 weeks you will likely have to decrease your calories further. This will help you to continue to match your current body’s caloric needs to your deficit.
HIGH PROTEIN
You may have heard that high protein diets are a strategy that people like to use. This is because eating higher in protein is a double win for fat loss goals.
First, it helps you to burn more calories when you eat it, because of TEF (thermic effect of food). Second, because of its impact on our satiation levels (feelings of fullness for longer), it can also be a phenomenal strategy to keep your caloric intake lower due to less hunger.
For individuals who don’t necessarily want to track their calories, eating more mindfully with higher protein in the diet can help to achieve a couple of wins without necessarily focusing on tracking calories as a whole!
If you are tracking calories as your method, you can aim for a slightly higher protein intake of around 25-35% of your diet. Play around with works best for you, and remember to work your way up slowly from where you are now. If you’re only getting 10% of your diet as protein, increase to 15, then 20, then 25% to allow yourself to build the habit and adjust to the changes.
The easiest protein sources to work with on your fat loss journey are more of the lean protein options like; eggs or egg whites, chicken breast, lean ground turkey, tilapia, tuna, etc.
CARBS WITH FIBER
Many people avoid carbs altogether when they’re trying to lose fat, but the problem with this is that it will help you see weight loss, but its not all because of fat loss.
If you enjoy eating lower in carbs even when you’re not cutting, then this is one thing. But your body uses carbs as its main and preferred energy source. If you’re cutting calories already to get into your caloric deficit, you don’t want to also drastically limit your carbs; you’ll feel the hit of your energy tank this way.
What you need is healthier, less processed carbs. A great strategy when it comes to your fat loss journey is to eat carbs that are higher in fiber. Increasing your fiber, just like increasing protein, increases your satiation levels and feelings of being full & satisfied after eating. Much different than carb sources that lack fiber (like cookies or chips).
Carbs with higher fiber sources include veggies, fruits, and whole grains. You can eat larger volumes of these types of carbs and still remain in a caloric deficit. This helps us to feel full, energized, and also provides us healthier food options when we’re already limiting them in a deficit.
You can also add low sodium spices for flavor, like Mrs. Dash, to change up the vibe so you don’t get bored!
The goal for your carb intake can be anywhere from 45-65% of your diet. There is leeway in how you want to balance your carbs. Find the amount that feels best for you, but keep in mind that carbs provide more than just calories to our body — so limiting carbs too strictly can have negative impacts in the long-term for already healthy individuals. There is purpose and health benefits for eating wholegrain, fiber-based carbs.
PAY ATTENTION TO FATS
When it comes to your fat intake, you want to be mindful of how much you are actually consuming vs. how much you think you are consuming.
Because fats have more than double the calories per gram, it’s easy for calories to add up with small portions. A slice of cheese or scoop of peanut butter is going to be more than double the calories of what carbs and proteins would be.
Fats are necessary in our diet for absorbing fat-soluble vitamins, and for hormonal health. That said, visually the amount of fats we’re eating should look much lower than the other portions of food due to how dense fat is.
A good strategy when it comes to fats is to learn about where all of your fat sources are in your everyday meals. For example, do you cook with fats like butter or olive oil? Are there any fats added into your snacks and desserts? Check your food labels. Keeping the frequency of saturated/trans fats low will allow you to open up more room for feeling satisfied and energized for much longer.
Opt to choose foods like nuts, natural nut butters, olives, egg yolk, avocados, and other mono/poly-unsaturated fats as your main fat sources — over things like cooking oils and more processed snacks (like chips) as your fats.
MINIMIZE ALCOHOL
It is really, really hard to not be negatively impacted by drinking alcohol. But its extra hard when you’re on a fat loss journey.
When it comes to including alcohol in your diet for fat loss- its a triple whammy. Its higher in calories per gram (like fats), it negatively impacts your recovery, and it takes a hit on protein synthesis (essentially “canceling out” some of the protein that you had earlier in the day).
Drinking alcohol means that you’ll have to work harder at staying in a deficit and in regulating your system for recovery. The best strategy for your health and fat loss is to keep the intake as close to zero as possible throughout each month.
If you do end up drinking, its no the worst thing in the world, as long as its not often on your journey. It will also mess with your head (seeing the scale go up, the inflammation, etc). It really won’t impact your overall journey if its not consistent, but it will impact how you feel and this can have even stronger impacts about how you feel on your journey. Many people see the scale go up a few pounds or notice the bloating, and these are common experiences, up to a few days after drinking.
Don’t let yourself get in your head and feel like your fat loss journey is ruined if you do happen to be imperfect on your journey, though.
let’s talk TOTAL DAILY ENERGY EXPENDITURE
Your TDEE is the amount of energy that your body needs within a day to sustain your life and your current body composition. Just like calories, we can also categorize our energy expenditure into four main areas.
The four areas we use energy:
BMR: This is the base level of our set needs, if we were to do absolutely nothing in a day.
TEF: This is the energy it takes to convert the food we eat into usable energy for our body.
NEAT: This is the energy it takes for all of our daily life activities. This includes things like brushing your teeth, cooking, cleaning, pacing, and fidgeting. Essentially any and all simple movement is considered NEAT.
Physical Exercise: This is the energy it takes for more strenuous activities like lifting, running, or other sports.
On your fat loss journey, you have the ability to increase your TDEE in all four areas. You can choose one, some, or all of these as strategies to focus on along your journey.
BMR
BMR stands for Basal Metabolic Rate. This is the largest area in which we burn calories each day. Your BMR is based on a combination of factors such as: body composition (fat and muscle mass ratios), height, weight, genetics, and hormones. This will make up to 60-75% of most peoples’ TDEE needs.
Despite being our biggest category for energy-usage, there is very little that you can do to change your BMR in the short-term. If you care about your long-term ability to burn more calories, though, this is where you can really make a bang for your buck with consistency.
If you incorporate resistance training in your routine (like lifting weights) as part of your strategy, it can give you long-term fat loss benefits of increased muscle mass. Over months and years, your BMR will start to increase as your muscle size begins to increase. The more muscle, the more your base level of needs rise for you to sustain that muscle. This then leads to being able to eat more, while not having to work as hard to stay lean. This is one reason many people recommend lifting weights.
This is a long-term strategy, but one that is worthwhile.
TEF
TEF is your Thermic Effect of Food. This is how much energy you need to metabolize and break down the food we eat each day. It can make up a range from 5-15% of our Total Daily Energy Expenditure. This depends further on the types of foods that we’re eating and how much we’re eating.
A common and useful strategy for fat loss is to increase your protein intake. As mentioned before, this helps with both increasing our TDEE (through TEF) and decreasing our caloric intake (by helping with satiation). Protein takes the most energy for our bodies to break down. It can take anywhere from 20-30% of energy to digest and metabolize protein within our body.
Carbs specifically with high fiber can also be a great strategy, concerning this category. Complex carbs like veggies and whole grains can take more energy to metabolize— around 5-10% of the calories consumed.
Fats take the least amount of energy to digest, taking up 5% or less of calories to digest. They are the most calorically dense, and take the least amount of energy to digest. Still, some fats are necessary for our diet in absorbing fat-soluble vitamins.
NEAT
NEAT stands for Non-Exercise Activity Thermogenesis, and it includes all movement outside of your physically demanding exercise. This is one of the top strategies we recommend for fat loss goals because it helps negate sedentary lifestyles and keeps recovery levels high. On average, this takes around 15% of our energy within a day, but it can be more or less depending on how much movement you’re doing. Someone living in walk-able NYC is going to have a different percentage than someone living in Arkansas, where everything requires or favors driving.
That said, there are so many ways that you can naturally increase your movement throughout the day without actually “working out.”
A popular method used to increase your TDEE is to increase the amount of steps you’re taking within your day. Some of the top examples of increasing your NEAT is: parking further away when you go to the store, taking the stairs not the elevator, and just going for walks in general. Around the neighborhood, hikes, walking trails, around the mall, on the treadmill; however you prefer.
But also doing household chores, standing at your desk instead of sitting, or stretching instead of just laying on the couch are all things that can also help with this energy expenditure. This strategy is great for increasing overall activity levels without drastically increasing your recovery demands. Its also a great strategy for individuals who struggle with low energy & motivation.
I would recommend nearly everyone incorporate some form of NEAT as a strategy in their routine.
PHYSICAL EXERCISE
Physical exercise can be anything that is strenuous work; whether it be lifting at the gym, going for a run, or working an intense construction job. This can account for up to 10-30% of your energy. This is one of the most controllable areas of energy expenditure.
With physical exercise, you’re able to expend a quick burst of energy in a short amount of time. Adding in a few workouts into your week is one of the easiest ways to increase energy levels. If you’re not already working out consistently, adding in just a little more exercise and movement can be an easy but impactful way to help to create a calorie deficit.
Many people tend to automatically think running or cardio as the only way to lose fat. But lifting weights can also be highly impactful for fat loss. In fact, it is even more impactful for individuals struggling with higher body fat levels. Lifting creates less impact on the joints than jogging, while still being able to challenge yourself physically. Other forms of exercise may be hiking, riding bikes, roller skating, jiu jitsu, dance classes, group classes, calisthenics training, recreational sports, and there are so many other options that fit into this category!
There are health benefits to adding both a form of cardio and resistance training to your routine, and this is what we would recommend for most individuals!
WHAT TO DO FROM HERE?
In order to figure out where to start on your journey, you need to first decide which methods will be easiest for you to incorporate. Choosing the easiest changes will help you to ease into this journey.
If your journey involves tracking calories or macros, its good to first start with finding your maintenance calories and do a nutrition assessment. This will help you figure out how much calories to set for your deficit, along with being able to analyze your current nutrition habits through the assessment.
Decide on how you want to measure your progress. There are a few different ways: weekly weigh-ins, body fat scales, DEXA scan measurements, circumference measurements, or progress pictures. My favorite options for fat loss are body fat scales that show your weight and estimated body fat percentage. Circumference measurements are extremely helpful as well, especially when also dealing with body recomposition and building muscle along the journey as well.
Its best to monitor your progress on a weekly basis to be able to navigate and adjust the plan as needed. You’ll know you’re achieving a healthy caloric deficit each week if you’re losing anywhere from 0.5-1 lbs lost per week on average throughout the month. If your body fat levels are on the higher end, you can aim to lose up to 2 lbs per week. Just make sure that you’re prioritizing your overall wellbeing and that you still feel balanced along the way.
You can always aim for less of a deficit, to ease into it and adjust better as needed. The goal of your fat loss journey is that you remain as balanced as possible, so that your body can adapt better to these changes.
A WARNING ABOUT OVER-DOING IT
The deeper into a deficit you go, the more fat you are going to lose. That said, you don’t want to go balls to the wall with cutting calories or over-exercising. This is a good way to crash, burn, and throw yourself out of homeostasis — creating further problems.
You also don’t want to allow yourself to get too lean. Our bodies need a certain level of fat for survival, so we never want our body fat levels to reach 0% (or to even get close to that). A healthy range for women is between 16-31% body fat and for men is between 7-24% body fat.
The best way to go about your journey is to make it easy and implement things slowly. Add things in as needed if you hit a plateau.
And remember too, that if you’re not losing fat, you’re not in a calorie deficit. And just because you’re not losing weight on the scale doesn’t mean that you’re not losing fat.
TLDR:
Fat loss requires a calorie deficit
Decrease calories by 100-200 from your maintenance
Eat higher in protein
Eat more carbs with fiber (like veggies)
Watch your fat & alcohol
Incorporate both strength training & cardio
Move more throughout the day
Do you want guidance and structure on your fitness journey? Apply for 1-on-1 coaching for custom training programs, form feedback, nutrition and more!
Sources
Chung N, et al. Non-exercise activity thermogenesis (NEAT): a component of total daily energy expenditure. J Exerc Nutr Biochem. 2018. https://pmc.ncbi.nlm.nih.gov/articles/PMC6058072/
Traynor P. Using food choice to boost metabolism: The thermic effect of food and weight management. Tahoe Daily Tribune. 2025. https://www.tahoedailytribune.com/news/using-food-choice-to-boost-metabolism-the-thermic-effect-of-food-and-weight-management/
Braverman J. What Is Body Composition? WebMD. https://www.webmd.com/fitness-exercise/what-is-body-composition
