Why Your Calorie Target Shouldn't Stay the Same for Months
Your calorie target should be adjusted often and not fixed for months, no matter if you’re trying to lose weight or gain it. Research shows the body adjusts how efficiently it uses energy while you’re actively in a calorie deficit or surplus, separately from the weight itself changing. If a calorie target is never revisited, it simply stops reflecting what’s actually happening to your body, which is one reason stalls towards your goal can feel very unfair, even when your effort level hasn’t changed or even increased.
In brief
- A calorie target is guidance to review regularly, not a fixed instruction for months.
- Your energy use can change while you are losing or gaining weight.
- Those changes vary between people, so a target that once worked may drift out of date.
- A stall can mean your target needs updating, not that your effort has failed.
Why does this happen when you’re losing weight?
This is called metabolic adaptation, your body doesn’t just burn fewer calories because you weigh less, it can also become somewhat more efficient on top of that, completely independent of the weight you’ve been hard at work losing. Research has measured this directly, and just like most things with the human body, not everyone experiences it the same way. Some people’s metabolic rate barely shifts, and a minority even see it move the other direction, which is why it’s key to keep adapting your calorie target as you move towards your goal. It’s also part of why two people eating the same amount can lose weight at quite different rates.
Does this fade, or is it permanent?
Sadly, this part is genuinely still debated among researchers. Some studies suggest the effect shrinks once weight settles at a new level, other researchers argue it can persist much longer than that. Nobody’s claiming certainty here, which is itself a reason not to trust a target that was only ever calculated once and never revisited.
What about if you’re trying to gain weight?
There’s evidence of something similar in reverse. In another study, people were deliberately overfed by the same fixed amount each day, and how much fat they actually stored varied roughly tenfold between individuals, an effect closely linked to how much their unconscious daily movement (fidgeting, posture, general restlessness) increased in response. That unconscious movement has a name, NEAT, and it can shift by hundreds of calories a day without anyone deciding to change anything. A fixed surplus that works well for one person may do very little for another, and that response also isn’t guaranteed to stay constant over time.
Why a fixed target can miss all of this
A calorie target calculated once and then left alone can’t account for your body’s changes, because these effects are about how your body is responding right now, not what your stats were on the start of your journey. Many tracking apps only revisit your target when you manually update your details, or offer a fixed guidance only once when you first use the application.
What this actually means for you
A stall may not be proof that a deficit or a surplus has stopped working. It can just as easily mean the your target quietly drifted out of date. Reframing a stall this way can really change how it feels. It’s less like a personal failure to push harder, and more like your guidance is out-of-date, in the same way you’d expect a GPS to recalculate after a wrong turn rather than blame you for not walking fast enough.
This is the specific problem Ori’s adaptive weekly target is built to address, whatever your goal is, be it to lose, gain or maintain your current weight. Instead of calculating a number once and leaving it, it looks at what’s actually happening with your weight and food trends every week and moves your personal target to match.
Sources
- Tissue losses and metabolic adaptations both contribute to the reduction in resting metabolic rate following weight loss - International Journal of Obesity (Fox et al., 2022)
- Metabolic adaptation is an illusion, only present when participants are in negative energy balance - American Journal of Clinical Nutrition (Martins et al., 2020)
- Metabolic adaptation: is it really an illusion? - American Journal of Clinical Nutrition, response (Ravussin & Redman, 2020)
- Role of Nonexercise Activity Thermogenesis in Resistance to Fat Gain in Humans - Levine, Eberhardt & Jensen, Science, 1999
A gentle safety note
Ori supports general wellness. It is not medical care. If you have a history of disordered eating, are pregnant or breastfeeding, take medicines that affect weight or appetite, or have a clinical nutrition need, speak with a qualified healthcare professional before changing your intake or weight goal.
Read Ori's Health Disclaimer