Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
After dieting, it’s pretty common to feel like your body’s struggling to get back on track. If you’re dealing with unexpected weight gain, constant tiredness, or feeling cold all the time, your metabolism might be out of whack.
In this article, we’ll explore some proven strategies to get your metabolism back up and running, so your body can start processing energy efficiently again.
Damaged metabolism refers to a state where your body's ability to efficiently convert food into energy is impaired. This can happen after periods of restrictive dieting, excessive exercise, or stress.
When the metabolism is damaged, you might experience symptoms, including:
Feeling more tired: If you’re constantly exhausted, even after resting, it could mean your metabolism has slowed down, making it harder for your body to produce energy.
Weight gain: Gaining weight despite eating less? That’s a common sign something’s off with your metabolism.
Feeling cold: Noticing you’re colder than usual? A slower metabolism means your body isn’t producing as much heat.
Slow healing: If injuries or cuts are taking longer to heal, it might be because your metabolism isn’t working fast enough to repair and grow new cells.
Hair loss: A sluggish metabolism can mess with hair growth, leading to noticeable hair loss.
Mood swings: Metabolic issues can affect brain chemicals, which might leave you feeling moodier or even depressed.
Extreme dieting can throw your metabolism out of whack in a few key ways. At first, you might see fast results, but your body quickly adjusts to fewer calories by slowing down its metabolism to save energy. Here’s what happens:
Lower calorie burn: When you cut too many calories, your body learns to conserve energy, which lowers your resting metabolic rate.
Hormonal imbalance: Crash diets can mess with hormones that control your metabolism and stress levels.
Muscle loss: Without enough protein, dieting can lead to muscle loss, which slows down your metabolism since muscle burns more calories than fat.
Starvation mode: Your body goes into energy-saving mode, which can seriously hurt your metabolism.
Nutrient deficiencies: Not getting enough nutrients from restrictive diets can mess with your metabolism and energy production.
Getting your metabolism back on track after dieting takes some smart changes. Below are 9 ways to help boost your body’s energy system:
Protein is crucial for repairing and maintaining muscle, which plays a big role in keeping your metabolism active. Your body burns more calories digesting protein compared to carbs or fats due to the thermic effect of food. Incorporating lean meats, legumes, eggs, and dairy into your meals can help rebuild muscle and boost your metabolic rate.
Water does more than keep you hydrated—it supports a healthy metabolism. Drinking enough water can temporarily increase your energy expenditure, even when you’re resting. Research suggests that drinking about 500 ml of water can raise your metabolic rate by up to 30% for 10-40 minutes. Make sure to sip water regularly throughout the day.
Building muscle is key for reviving a sluggish metabolism. Muscle tissue burns more calories than fat, even at rest, so the more muscle you have, the more calories you burn. Regular strength training can help reverse the muscle loss that often happens with dieting, keeping your metabolism working efficiently. According to research, a 45-minute intense workout can keep your metabolism higher for up to 14 hours.
Eating consistently throughout the day can help stabilise your blood sugar levels and keep your metabolism from dipping. Research shows that how often you eat and which main meal you skip could be linked to metabolic syndrome.
When you skip meals, your body goes into energy conservation mode, which can slow your metabolism and lead to overeating later. Spacing out your meals helps keep your energy levels up and your metabolism engaged in processing food.
Quality sleep is critical for a healthy metabolism. A study shows just one night of poor sleep can raise ghrelin levels, which is a hormone that stimulates appetite, making you feel hungrier. So, making sure you get around 7-9 hours of uninterrupted sleep per night can help stabilise these hormones and maintain a healthier metabolic rate.
Chronic stress can disrupt your metabolism by increasing cortisol, a hormone that encourages fat storage and can slow down your body’s energy-burning processes. Finding ways to relax, whether through meditation, exercise, or hobbies, can help keep your metabolism in check.
Boosting your intake of omega-3 fatty acids can do wonders for your metabolic health. You’ll find these healthy fats in fish like salmon and mackerel, as well as in flaxseeds and walnuts. Omega-3s are known for their anti-inflammatory properties, which can improve insulin sensitivity and ramp up your metabolic rate. Regularly enjoying omega-3s comes with plenty of perks, including better heart health and reduced inflammation, helping keep your metabolism in check.
If you're curious about calorie counting, check out our article on debunking the ‘Calories In, Calories Out’ myth.
Want to give your metabolism a little kick? Try adding some spicy foods to your meals. Ingredients like chilli peppers pack a punch with capsaicin, which can spark thermogenesis—the process of generating heat in your body, leading to more calories burned. Studies have shown that capsaicin can boost energy use, help burn fat, and even reduce appetite. So, don’t be shy; throw some spicy condiments or peppers into your dishes to elevate your metabolism and support your weight management goals.
Your thyroid gland is a key player in regulating your metabolism by releasing thyroid hormones. If you’re facing ongoing metabolic issues despite making healthy changes, it might be worth getting your thyroid checked. An underactive thyroid (hypothyroidism) can slow down your metabolism, causing weight gain and energy dips. A simple blood test can help diagnose any thyroid function issues, allowing for targeted treatments to get your metabolism back on track.
Fixing a damaged metabolism after dieting is key to feeling healthier and more energetic. It’s not just about eating less or working out more; it’s about taking care of your body as a whole.
Start by adding more nutritious foods to your meals, focusing on protein, and managing stress. Giving your body enough rest and staying hydrated are also important for getting your metabolism back on track.
This process takes time, so be patient with yourself. By making these simple changes, you can boost your metabolism and enjoy better energy and well-being. For more effective results, join our Interval Weight Loss program for expert guidance.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.