Fast Track to Fat Loss? The Truth about Caloric Deficits
Calories Are More Complicated Than You Think
If you think the best means of achieving fat loss is simply cutting calories, you’re not alone. In fact, when most people think of dieting that’s what comes to mind—smaller portions. And from the outset, they’re not entirely wrong.
Calorie restriction diets have been shown to have a positive effect on longevity, meaning a low-calorie diet can slow aging and help you live longer—but so can lowering your body fat percentage. And if that’s your goal, this is where things get a bit tricky. You see, a low-calorie diet can also lead to weight loss—but that isn’t necessarily a good thing.
By depriving your body of nutrition to an excessive degree, not only will it make use of fat stores but it will also take advantage of any breakdown of muscle tissue and utilize those proteins as fuel as well. Your goal should be fat loss, while maintaining as much lean mass as possible.
This is why Dr. Jim Stoppani—one of the world’s foremost experts on fitness and nutrition—so often recommends that you eat as much as you can while still achieving the goal of steady fat loss, and as you’ll see below science supports that.
“Fat loss is a continual process and your diet must change gradually over time,” says Stoppani. “The worst thing you can do is immediately jump down to a very low amount of calories and carbohydrates.”
The preservation of muscle tissue is paramount in the quest for a leaner physique, which is why the principles laid out in his Dieting 101 plan for fat loss focus on macronutrients—protein, fat, and carbohydrates—not calories alone.
The truth is, metabolism and fat loss are a bit more complicated than the common refrain of “Calories in vs. calories out” suggest. As you’ll see, the variables at play are numerous. And while there is complexity to these processes, once you have an understanding of them the solution is dead simple.
Caloric Deficits — A Gross Oversimplification
The way this misguided approach is most often shared goes something like this: “You just need to make sure you’re taking in less calories than you’re using.” More specific advice may include actual calorie amounts, such as cutting 500 calories per day from your diet to total 3,500 calories per week. One pound of fat equals 3,500 calories, so that’ll mean one pound lost per week, right?
Not so fast.
You see, calories aren’t static units. Where the calories come from, how the body uses them, your genetic predisposition, and your level of activity all factor into how your metabolism functions. Your total daily energy expenditure (or TDEE) is a combination of factors: Resting metabolic rate (RMR), the thermic effect of food (TEF), and physical activity. And it’s difficult to know exactly what your daily expenditure is in calories without laboratory analysis, because of the above variables.
Every body is different. This should come as no surprise, but it’s often neglected when it comes to fitness advice. One-size-fits-all recommendations, like a cookie-cutter caloric deficit approach, may produce some results, but they’re far from optimal, and for too many fail entirely. When it comes to fat loss, you need to consider the way your body works, and your specific needs in order to get the most out of your fat-loss efforts.
Considering the Variables — What Makes You, You
The process by which the body metabolizes fuel is by no means a simple thing. It takes a host of nutrients, minerals, and bodily chemicals working in concert with each other to utilize fuel from foods or storage like fat and even muscle tissue.
One such chemical is insulin, the hormone that regulates blood sugar levels and the release or storage of free fatty acids in the body’s fat cells. The production of and sensitivity to insulin varies from person to person, however. Poor insulin response leads to metabolic disorders and is a chronic issue for diabetics.
Thyroid function also plays a part in metabolism—an overactive thyroid greatly increases metabolism to a sometimes unhealthy degree, while an underactive thyroid can all but kill your metabolism.
These are just two examples of the many factors that contribute to the uniqueness of each individual’s ability to metabolize fuel, and why a calorie to one person is not the same as the calorie to another.
Additionally, body composition—the ratio of body fat to lean mass—affects overall metabolism. Muscle mass burns more calories at rest, contributing to your resting metabolic rate. Body fat has the opposite effect—the higher your body fat percentage, the slower your metabolism.
Calories In — The Thermic Effect of Food
Another factor worth considering is what’s known as the thermic effect of food. Most simply put, the body has to work to break down, utilize, and store nutrients, and the energy used counts toward your total daily expenditure. On average, this amounts to 5–15% of your overall caloric intake. How much energy is required depends on the macronutrients being digested.
Fats require almost no effort, offsetting 0–3% of the calories they provide. Carbohydrates use up 5–10% of their caloric value when being metabolized. Protein, on the other hand, requires as much as 30% of its caloric content to be metabolized, utilized, and stored. This is one of the reasons Dr. Stoppani has long argued that a high-protein diet boosts fat loss.
It’s also a reason to question the concept of caloric deficits, as it fails to account for the composition of not only your body but your diet as well. Simply put: All calories are not created equal.
Calories Out — The Effect of Exercise
The final variable to consider is activity level, and how well the body responds to it. As our bodies tend toward optimum efficiency, even a high daily activity level can have little to no impact on your metabolism.
If you’re training regularly, you may see a more appreciable boost in your total daily energy expenditure. Using methods recommended by Dr. Stoppani like high-intensity interval training (HIIT)—cardio performed in quick intervals of maximum effort and rest—to boost fat loss, or periodization—progressive changes to weight and rep schemes—to prevent stalled progress, you’ll see an even more pronounced effect.
Dr. Stoppani explains: “The major reason that HIIT works so well to drop body fat to a greater degree than continuous steady-state cardio appears to be due to the greater increase in resting metabolism following HIIT.”
Most of the calorie use from workouts actually takes place afterward due to excess post-exercise oxygen consumption, or EPOC. This is what makes HIIT so effective, as it boosts EPOC far more than steady-state cardio. But as with your resting metabolic rate, there’s no knowing exactly how many calories you burn without analysis performed in a lab.
Adding one more complication to matters is the fact that exercise boosts the thermic effect of foods, thus compounding the resulting calorie use.
Caloric Deficits — Killer Metabolism or Metabolism-Killer?
As remarked on in the past, by reducing lean muscle mass along with body fat, overall metabolism is slowed. This leaves your body less capable of continuing to reduce body fat, or worse, less able to avoid regaining body fat in the long run.
It’s easy enough to explain this because, as stated above, muscle tissue burns more calories at rest, so less muscle tissue means a slower metabolism. But research has explored the connection between this phenomenon and caloric deficits in detail. Not only does a low-calorie diet slow metabolism, it also reduces the thermic effect of foods, and it even reduces overall energy use during exercise.
That’s right—a caloric deficit makes exercise less effective for fat loss.
One phrase you may hear when discussing caloric deficits and low-calorie diets is “starvation mode.” This kind of phrasing can make the situation sound pretty dire—and if you’re struggling to shed fat, it may well be.
The body, in general, is excellent at maintaining itself efficiently. Homeostasis is the tendency toward balance, and it’s necessary for overall survival. When the environmental temperature is cold, for example, the body ramps up thermogenesis by burning more fat and calories to keep the body’s temperature at the usual 98.6 degrees.
The same is true in the way the body adapts to its most efficient under repeated stress like activity, which is why training protocols should be changed using a method like periodization, as mentioned above.
If nutrition is suddenly reduced, the body will adapt in another way—by slowing your metabolism to preserve energy stores, i.e. body fat. So rather than speed up the process, a low-calorie diet can stop fat loss entirely.
One study, however, arrived at some insights that by now will prove unsurprising to you. While researching the impact of caloric restriction on resting metabolic rate, they found that subjects did not lose lean mass as expected.
Now, there are some flaws in the way this study was performed: Subjects’ diets were not particularly controlled, and in fact they were counted on to report on their dietary intake themselves. However, the results were clear enough, albeit not the focus of this particular study. Researchers speculated in their conclusion:
“The calorie deficit, macronutrient distribution and rate of weight loss may be key factors in the retention of fat-free mass and resting metabolic rate. Dietary information should be prescribed and described on an individual basis, i.e. kilocalories or grammes of protein per kilogram body weight, rather than by group means, as in this study.”
They discovered what Dr. Stoppani has been saying for years: Tailoring a diet to your needs and focusing on macros are the key to fat loss.
Lastly, another study proved the point even further. These researchers separated subjects into three groups—all of them relatively low calorie, but focusing on macros. One group’s diet was low carb, the second’s low fat, and the third low carb but with an additional 300 calories compared to the other two.
Even though they ate 300 more calories per day than the group on the low-fat diet, they still lost more overall weight. Eat more to lose more—who doesn’t like the sound of that?
In the end, it’s obvious that not only do you require sufficient fuel to keep your metabolism going, the content of that fuel truly makes a difference. When it comes to fat loss, the macro is king.
The Real Answer? Macros Matter Most
As you can no doubt see, given the uniqueness of your body’s processes and variables like diet composition and effects of exercise, blanket recommendations for caloric deficits that fail to take these factors into account can be horribly inaccurate.
Each person’s use of calories differs. Calories are not fixed. Even the value of currency fluctuates—so too does the value of a calorie. That’s why Dr. Stoppani has long recommended focusing on macros, not calories: If you take care of your macros, calories will take care of themselves.
In truth, if you’re eating healthily and exercising, you’re likely already at more of a caloric deficit than you think—particularly if you switch to a plan like Dr. Stoppani’s Dieting 101 and a diet high in protein, possessed of moderate fats, and adjustments to carbohydrates for your goal of fat loss. Your new lifestyle alone will affect a change in your calorie balance, without leaving you feeling deprived of nutrition.
Add a fat-loss focused program that includes periodization and HIIT like Dr. Stoppani’s Super Shredded 8, and you’ll increase fat loss all the more.
The bottom line is, “caloric deficits” is an oversimplification. There are too many factors that complicate such a black-and-white view of how metabolism functions. But the answer to fat loss is still simple: Focus on macros rather than calories.
By getting the right balance of protein, fat, and carbs, and training properly, you will see a change in body composition. You’ll definitely be making use of the calories you eat, and cutting calories even further based on some arbitrary number with little mind as to which macros those calories come from can not only be ineffective—it can be downright counter-productive.
Want to know more? JimStoppani.com features hundreds of articles and videos from Dr. Jim Stoppani himself, on everything from nutrition to supplementation and training.
