Fixed calorie recommendations do not work. They must be customized to each individual.
The calculator shows how many calories you may eat to maintain or lose weight. Do your best estimate of how much exercise you will be stick to. Be honest.
The recommended calories include exercise – so don’t try to adjust what you eat each day if you had a workout.
Over time, as you lose weight you will need to recalculate based on your new weight. Also, if you make big changes to your workout (reducing or increasing), you should recalculate.
Science tells us that 1 pound of fat equals 3500 calories, so a daily calorie deficit of 500 should result in 1 pound per week of fat loss.
In reality, things don’t quite work that efficiently.
Generally, your energy expenditure becomes less as you lose weight, meaning you will inevitably plateau. The amount of food intake that once resulted in weight loss will now only maintain2.
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Always try to aim for the "Fat Loss" daily calorie level.
The "Extreme Fat Loss" level is the lowest calorie level you should ever try. Do not attempt to immediately drop your calories to this level hoping for a quick fix. This may ultimately backfire.
Why use the 7-day Calorie Cycle (Zig-Zag)?
The human body is remarkably adaptive and quickly adjusts to a lowered calorie level.
It becomes more efficient at using energy (lowered metabolism) and therefore burns less fat. This is why most of us reach a weight loss plateau.
At this point, the only option is to change something:
You often find that the nearer you get to your goal weight (or body fat percentage) – the harder things get!
Continually dropping calories will only lower metabolism even further. The moment you return to ‘normal’ eating – the weight comes back on. The 7-Day zig-zag suggests daily calories that will keep your body guessing – and increase your chances of sustained weight loss.
It is difficult to set absolute bottom calorie levels because everyone has different body composition and activity levels.
Health authorities do set some baselines – these are 1200 calories per day for women, and 1800 calories per day for men.
These rules don’t make sense – are you a sedentary person with little muscle mass? Or someone who is tall, muscular, and exercises a lot? Absolute levels don’t work – but do give us a starting point.
Try not to lower your calorie intake by more than 500 calories below maintenance.
Doing so may invoke the body’s starvation response, which can lead to a Yo-yo dieting effect.
Try to gradually lower calories. A sudden drop (such as 500 calories or more) can cause your metabolism to slow.
Learn to eat slowly – research shows that faster eaters are heavier people1.
You are completely set up for a regain in fat if you suddenly return to your previous eating patterns.
As your exercise level was already factored into the equation, there is NO NEED to subtract calories burned by exercise.
For the sake of simplicity we define a ‘workout’ as 15-30 minutes of elevated heart rate.
For you this could mean a brisk walk, for others, it could be a slow jog. It could be a session of weight-bearing exercises.
Intense exercise can be defined as an hour of elevated heart rate (however intense workouts such as a series of body weight exercises (or heavy weights) with little or no breaks are considered intense even when only a shorter duration).
Estimating your exercise can be very arbitrary. If in doubt – underestimate. We all tend to overestimate how much exercise we do.
Uses the calories burned tool to see how different exercises compare.
You can lose weight without exercise. However exercise will bring other benefits: it maintains muscle when under calorie deficit, and is great for your heart and mental health.
Most people lose muscle mass when restricting calories.
Body recomposition takes real effort. It requires a delicate tweak of daily calories, combined with a comprehensive workout plan.
This calculator has been developed using the most accurate methodologies from peer-reviewed research. See the Calorie Needs Guide for a complete explanation.