Caloric Deficits and Fat Loss
By John P. Hussman, Ph.D.
All rights reserved and actively enforced.
The secret to fat loss is simple. It's called a "caloric deficit."
For every pound of fat you want to lose, you have to burn 3500 more calories than you take in. If you accumulate persistent caloric deficits day after day, you will lose fat. This is not a theory. It's a law of physics.
My main page, http://www.hussmanfitness.org, explains the science and techniques to help you to burn more calories, raise your metabolism, improve your fitness level, and build muscle.
A complete program includes resistance training, aerobic training, interval training (get winded and recover, get winded and recover), cross training (alternating two different exercises on different days, e.g. treadmill and exercise cycle), small frequent meals containing high-quality protein and carbohydrate, and low-glycemic nutrition (avoid a lot of refined sugar, white flour, and highly processed carbs - focus on carbs that exist in nature). Proper supplementation, particularly post-workout whey protein or leucine, is helpful (see my main page). Lots of water and sufficient rest are also a must.
These are proven techniques that can transform your body and improve your fitness level. Unfortunately many so-called weight loss strategies are really muscle loss strategies. These include severe restriction of carbohydrates (the Atkins diet, for example) and excessive training without proper post-exercise nutrition. Eating too much in the way of simple, processed carbohydrates (white flour, sugar) also kicks up insulin, which prevents fat burning until the insulin clears the system (which can take a while if you've got insulin regulation problems).
My hope is that the information on this site will help you succeed while avoiding the pitfalls. While the components of a proper fitness program may seem like an overwhelming list, they're actually very simple when you break them down into daily actions.
Before you begin - Know how to measure progress
If your goal is fat loss, the scale is an extremely poor tool for measuring progress, particularly when you are doing any kind of weight training. Also, there is so much variation in water retention and digestive contents that you really cannot get a useful reading until your fat loss is significant as a percentage of your body weight.
The mirror is another poor measuring tool. Fat never spot-reduces. It comes off in proportion to the existing fat layer. This is why you can estimate your body fat percentage by measuring the skinfold at just one or two locations (The clunky but consistent Slim Guide caliper is about $20, which you can get at http://www.bodytrends.com/cre874.htm. I prefer it to electronic gadgets, which can be very temperamental. You can interpret your suprailiac readings using my caliper calculator: http://www.hussmanfitness.org/caliper.htm). Usually, the shoulders and upper body are the first to show visual improvement, since these are the areas where the fat layer is thinnest. Your "problem areas" are virtually never the first to show improvement. But the progress will come if you don't give up.
The way to measure fat loss is to use a combination of tools, and to focus on trends rather than single isolated readings. You should use waist circumference, the fit of your clothes, skinfold caliper readings, and changes in your trough-to-trough weight readings over a period of time. For instance, if you weigh yourself daily (preferably in the morning) your day to day readings will bounce up and down. I generally track the 7-day average of fat mass (body fat percentage times scale weight), which has fewer jumps and stalls.
In short, don't approach your fitness program demanding daily proof from the scale or the mirror. Go ahead and take measurements, but understand that there is day-to-day noise in those measurements from water retention, digestive contents and other factors that can be as much as 4% of total body weight. You have to take day-to-day fluctuations with a grain of salt and focus on a combination of readings from clothes, scale, calipers, and other tools.
I really believe that the key to success in nearly everything is DAILY ACTION. Find a combination of actions that you are confident will bring success if you follow them consistently. Then follow them consistently.
The rest of this page is intended to prove to you why creating a persistent daily caloric deficit should be one of those actions. Some people do very well following a portion rule (5-6 small meals a day, with a palm sized portion of protein and a palm sized portion of carbohydrate). But if that isn't working for you, it's time to track your caloric deficit directly.
A caloric deficit is simply the number of calories you take in, minus the number of calories you burn.
On the intake side, a good way to count calories is to think in terms of ingredients. A slice of bread is about 75 calories, as is a medium piece of fruit. A medium potato or a medium cup of oatmeal or steamed rice is about 150 calories. Dense, dry carbohydrates roughly double the calories (bagels, cereal or pretzels). A roasted skinless chicken breast is about 150 calories. Frying anything roughly triples the calories, as does putting it in mayo (tuna salad). Anything prepared with fat automatically adds 100 calories, as does a thin slice of cheese. The things that blow your calories out of control are fat, highly refined carbohydrates, and lack of water content.
For the first few weeks, write down everything you eat - even those two grapes - immediately on a 3x5 card (you'll learn a lot about yourself, and your daily estimates may not even be close otherwise). If you follow roughly the same meal plan every week, it is definitely worth the effort to carefully and honestly estimate the calories of your usual meals using a measuring cup and an inexpensive food scale. If you do this even once, you'll find that it's much easier to track your daily intake accurately.
On the output side, click here to estimate your "Base Metabolic Rate" (BMR): http://www.hussmanfitness.org/bmrcalc.htm. Your BMR is the number of calories you'll typically burn lying in bed all day. If you work out solidly with weights for about 45 minutes, or do aerobics for about 20-40 minutes (no more than 20 using high intensity intervals), you'll probably burn about 1.5 times your BMR that day. If you don't work out, but have a normal level of activity, you'll probably burn about 1.3 times BMR. If you've got a sedentary job where you're at a desk, or you're worried about a "slow metabolism", estimate 1.4 times BMR for workout days, and 1.2 times BMR on non-workout days. When scientists talk about "slow metabolism", they're hardly ever talking about shortfalls more than that.
Every day, take the number of calories you take in, and subtract the number of calories you burn. If you're trying to lose weight, you want this to be a negative number - a "caloric deficit." For instance, if you eat 1500 calories and you burn 2000, you've created a 500 calorie deficit that day.
Your main goal for fat loss is to accumulate a significant caloric deficit over the entire week. If you're aggressively targeting fat loss, try to keep your caloric intake close to or slightly below your BMR (but not more than about 10% below, or you'll tend to tire out easily). If you take a "free day", try to keep your intake below about 1.6-1.8 times BMR. If you do this, you'll accumulate a good, solid caloric deficit for the entire week.
In order to lose 1 pound of fat, you've got to burn 3500 calories more than you take in. This is true whether you have major fat loss goals (which was my challenge a couple of years ago), or whether your goal is maintenance and "cutting."
As your faithful lab mouse, I've taken some data over the past 4 months. My fat loss goal was modest: lose about 8-10 pounds of fat to cut my body fat percentage (my other goal was back and shoulder development). What you see below is a chart of exactly how the fat came off.
Specifically, there are two lines. The blue line is my cumulative fat loss. To get a reasonable fat estimate, I multiplied my morning scale weight times my body fat percentage to get "fat weight." Then I averaged the daily fat weight numbers over the prior week, which smoothed out the day-to-day fluctuations.
The red line is my cumulative caloric deficit (just a running total of the daily deficits, day by day), divided by 3500. I used 1.5 x BMR on workout days, but since I manage an investment company and work in front of trading screens all day, I used 1.2 times BMR for free days.
The graph below shows why a persistent caloric deficit is the key to fat loss.
When I first looked at this graph, even I was surprised. I knew that fat loss was related to my caloric deficit. But I had no idea how close that relationship was. Take a look early in the graph where the lines both go above zero. That's Christmas. Take a look near the end of the graph where they go up again. That's where I took a "spring break" to recover from a knee injury.
Notice also that I've measured fat loss by smoothing the figures over 7 days. Even with this smoothing, there are still points where the progress goes sideways for a while even though the deficits are accumulating. Then boom, both figures come back together. Too many people quit their fitness programs because the scale figures are unexpectedly high for a few days. Don't do this to yourself.
Focus on daily actions. Create a persistent caloric deficit. The results will come.
I hope that this helps! - John