Why Online Calculators Won’t Help You Lose Weight Long-Term
If your goal is to get fitter, lose body fat, and keep it off, relying on online calorie calculators might not be the best idea. Here’s why.
This morning, I got a message that said:
"Hey Peter, I used an online calculator to set my macros. It says I should eat 1600 calories a day to lose 30 pounds in 6 months. Does this sound right to you?"
This question highlights a common problem: calculators can’t adjust to how your body reacts to a calorie deficit.
Here’s what usually happens with calculators:
You start eating at a set calorie target (like 1600 calories).
You lose weight at first, but your body adapts. Your metabolism slows, hunger increases, and you burn fewer calories naturally.
When progress stalls, the calculator suggests eating even less—maybe 1500 or 1400 calories.
This cycle continues until you’re eating very little, feeling tired, hungry, and frustrated. Eventually, your body stores fat more easily when you eat more again.
This pattern, called "body fat overshooting," is why many people regain the weight they lose—and often gain even more.
So, what’s a better approach?
Here are some tips to help you lose weight safely and sustainably:
Support your metabolism:
Eat enough protein (about 2g per kg of your goal weight).
Strength train to maintain muscle.
Focus on high-quality foods and avoid staying on very low calories for too long.
Monitor how you feel:
Pay attention to hunger, cravings, mood, energy, digestion, sleep, and recovery.
If these go off track, pause your diet and eat maintenance calories for a while.
Be flexible:
Include foods you enjoy and make room for social events.
Balance out indulgences by adjusting your weekly calories instead of stressing over daily limits.
Think long term:
Follow a plan that helps you lose weight and maintain it for life, not just for a few months.
This is the method I use with my 1:1 clients. The key difference is having someone to guide you, adjust your plan, and keep you on track for results that last.
If you’re tired of trying to figure it all out on your own and want a personalised, science-backed plan, let’s chat.
Drop me a message, and we can discuss if my coaching program is a good fit for you—no pressure, just a conversation to help you reach your goals.
