Yesterday in the first article of this series, I explained what it takes to build a flat belly, and told you how to calculate your body fat percentage. Today I’m going to show you how many calories you need to eat to lose fat and flatten out your belly.
The rate at which you can lose fat depends on how much fat you currently have. The more fat you have, the faster you can lose it. The leaner you are, the more your fat loss slows down.
When it comes to calorie deficits, there’s a sweet spot. A tony calorie deficit won’t work- your progress will be so slow you’ll barely notice it, which will kill your motivation- and that’s if you lose weight at all. Your metabolism might just slow down enough to erase that tiny deficit.
On the other hand, more isn’t better. If your diet is overly aggressive, you’ll lose muscle mass, and won’t lose more fat than you would on a moderate deficit.
I’ll give you some guidelines in a moment- but first things first.
Calculating how many calories you burn is really complicated. The best way to do it is to use an activity tracker, like a FitBit.
A pound of body fat contains about 3750 calories. That means that to lose a pound of body fat, you need to burn 3750 calories more than what you eat.
Now with that said, here’s the rate of fat loss you should shoot for depending on your body fat percentage. Note that rates of fat loss are best expressed as a percentage of body weight, rather than a raw number- body one pound means something very different for a tall, obese person vs a short, skinny person.
Obese- men over 28% bf, women over 40%.
Target weight loss: 1.5-3% of body weight per week
If you’re obese, you should go on a protein-sparing modified fast, eating around 600-1200 calories per day, depending on your body weight. You still need to eat sufficient protein, fat and vegetables- I’ll discuss that in the next module.
Overweight- men 20-28% bf, women 30-40% bf.
Target weight loss: .75-1.5% of body weight per week
Average: men 15-20% bf, women 22-30% bf
Target weight loss: .5%-1% BW per week
Athletic: men 9-15% bf, women 14-22% bf (This is the goal range for a flat belly)
Target weight loss: .3-.6% BW per week
Ultra-lean: men under 9%, women under 14% bf
Target weight loss: .2-.4% BW per week
Got all that? Here’s an example calculation:
Suppose you’re a woman who weighs 155 pounds at 25% body fat- putting you in the “average” range. You want to lose between .78 and 1.55 pounds of fat per week. That amounts to a weekly deficit 2906 to 5812 calories.
That means that on average, each day you should eat 415 to 830 fewer calories than you expend. This won’t actually be steady from day to day- as I’ll explain in lesson 9, you’ll want to eat more on some days than others.
Of course, this calculation is just a starting point- your estimates of how many calories you eat and/or expend won’t be perfectly accurate.
You can infer what your deficit has been (roughly) based on your change in weight. If a week goes by when you don’t lose weight, you know you were eating roughly at maintenance, regardless of what your calculations said. If you lost one pound, you know your deficit for the week was about 3750 calories.
Why a range rather than an exact number? You can lose fat faster, without losing muscle, if you lift weights, keep stress to a minimum, eat healthy food, and sleep well. More on that in the next few lessons.
Ultimately, you have to watch the scale and adjust as needed. In the example above, if a week goes by and you only lost half a pound, you should reduce your daily calorie intake by about 200-500 calories to bring your weight loss into the target range.