If you’ve put the time, effort and consistency into losing weight, you may feel like the hard part is over. But for many people, keeping the weight off can be even tougher.
Your body may seem to “fight back” after weight loss. That’s because your metabolism can change in ways that make maintaining your new weight more challenging.
Jennifer Meyfeldt, MD, an obesity medicine specialist with Banner - University Medicine, explained more about why this happens and what you can do to maintain your weight loss.
What is metabolism?
Metabolism is how your body uses energy (calories) for its functions, like breathing, circulating your blood and digesting food, as well as for supporting your activity. Your metabolism isn’t set. It adapts based on your body and your habits.
How metabolism changes after weight loss
We used to think body weight was just about “calories in, calories out.” That’s the idea that you could balance the calories you eat with the calories you burn to maintain your long-term weight loss.
“Now we know it’s more complicated than that,” Dr. Meyfeldt said. “When you lose weight, your body changes its nerve pathways and hormone levels to try to bring the weight back. If you’ve lost weight and then gained it back, it’s easy to feel like you failed or didn’t have enough willpower but that’s not true. The weight regain is happening because you are facing an uphill battle against your changing metabolism.”
These factors can influence weight maintenance:
- Your resting metabolic rate may go down.
- Your body may increase hunger signals to try to regain the weight you lost.
- Your body needs fewer calories at a lower weight.
- Your body may become more efficient at conserving energy.
Why maintaining weight can feel harder
Maintaining weight loss can be hard because your body actively tries to regain the weight you lost. These changes come from your biology, not from a lack of willpower.
- After weight loss, hormones that control hunger and fullness shift, making you feel hungrier and less satisfied.
- Your metabolism can slow down, so you burn fewer calories than before.
- You may feel like you have less energy.
- Genetic factors can influence how strongly your body resists weight loss.
Together, these changes can make it easier to regain weight, even if you continue the same healthy habits that helped you lose weight.
What is ‘metabolic adaptation?’
Metabolic adaptation is the process that your body uses to slow weight loss or cause weight gain. It adjusts to fewer calories and protects you from starving when there is not enough food.
“This was important for our ancestors, who needed to maintain their healthy weight despite limited access to food. But it can be an obstacle for people with obesity who are trying to lose weight to be healthier,” Dr. Meyfeldt said. It can be a reason why weight regain happens.
Metabolic adaptation is a normal response. It can be temporary but without adjustments it can last.
Does metabolism slow down permanently?
Your metabolism never stops working and you can adjust or stabilize it with consistent habits. It’s important to make changes to support your metabolism if you want to maintain your weight loss.
The length of time for metabolism slowing is different from person to person. “We know from studies that even after six years, your metabolism might not be back to its normal state,” Dr. Meyfeldt said.
How to support your metabolism after weight loss
One important way to prevent weight regain is to be physically active. To maintain weight after a drastic weight change, you may need to get 300 minutes of moderate-intensity activity per week, whichis significantly more than the recommended 150 minutes per week for general health benefits.
You can start small and build short bursts of activity into your routine. As exercise becomes a habit and your endurance improves, you can gradually do more until you reach your goal.
It can also help to:
- Follow regular eating patterns
- Prioritize protein to support muscle
- Include strength training to preserve lean mass
- Get enough sleep
When weight regain may happen
You may find you start to gain back the weight you lost if you:
- Return to the eating patterns you followed before you lost weight
- Cut back on your physical activity
- Are facing stress, sleep disruption or hormonal changes
- Have a metabolism that keeps adapting to your weight loss efforts
When to consider medical support
It’s normal for your weight to change a bit. But it’s bad for your body to lose and gain weight repeatedly, which is called weight cycling or yo-yo dieting.
Talk to your primary care provider if you:
- Regain more than 5% of your body weight after weight loss
- Feel like you are in a loop of dieting and weight regain
- Have trouble managing hunger or energy levels
- Would like answers to questions about medications or structured programs
Your provider can help you rethink your nutrition plan and exercise routine or help figure out if you could benefit from a medication to help you maintain your goal weight.
The bottom line
After you’ve lost a lot of weight, your metabolism adapts in ways that can make it harder to maintain. With the right strategies and support, you can keep weight off for the long term.
If you’re struggling to maintain weight after losing it, a Banner Health provider can help you find a plan that works for you and supports your health.
FAQs
Does metabolism slow down after weight loss?
Yes, your body may burn fewer calories as it adapts to a lower weight.
Why is it harder to keep weight off than lose it?
Changes in hormones and energy use can increase hunger and reduce calorie burn.
Is metabolic adaptation permanent?
Not necessarily. It can improve with long-term habits and stability.
How can I boost my metabolism after weight loss?
Strength training, adequate protein and consistent activity can help support it.
When should I seek help for weight regain?
If maintaining weight feels difficult despite consistent habits.
