Boost your metabolism without dieting — here’s how

Woman holding a smoothie post-workout: diet and metabolism
(Image credit: Getty images)

You can boost your metabolism and improve your metabolic health by making just a few changes to your exercise regime, sleep hygiene, or stress management, but diet may be the biggest lever.

If you’ve renewed your promise of a “new year, new me,” — haven’t we all? — you might be considering new ways to manage your exercise and diet choices. But while throwing the kitchen sink at your latest health goals might seem tempting, the all-or-nothing approach rarely yields the lasting results we’re all after. 

Now that the seasonal overindulgence is over, it could be time to reboot your metabolic health without drastic dieting or calorie counting. We previously spoke to Lauren Kelley-Chew, head of metabolic health and glucose monitoring tech start-up, Levels (opens in new tab), to find out what metabolism is and why metabolic health matters. This time, we picked her brain to discover the role diet plays. 

Slow metabolism? This could be the secret to better workouts, according to our expert, who reveals the secret to better metabolic health below.  

Metabolism vs metabolic health

Kelley-Chew separates metabolism and metabolic health into two categories: metabolism is a set of biochemical processes that convert consumed food into energy for your cells to power your body, whereas metabolic health refers to how optimally these processes run. 

Signs of good metabolic health include stable energy levels and mood, a strong immune system, low risk of chronic diseases like Diabetes, and more. Metabolic health is scored across several markers like blood sugar, blood pressure, and cholesterol, which should sit naturally within a healthy range. 

Kelley-Chew adds that although you might get dealt a bad hand, you can improve your metabolic health with some simple and totally manageable changes. 

Does diet affect metabolic health? 

As we know, not all foods are created equal. “The foods we eat affect the body in several ways, from the peaks and valleys of glucose to the function of our cells,” says Kelley-Chew. 

“Carbohydrates directly impact blood sugar as they convert to glucose in the body. Eating high-carb foods can lead to blood sugar spikes and elevated insulin levels, which can be harmful over the long-term.” 

A single spike from your meal is nothing to worry about (although your mood and energy levels might take a knock), but you can maintain a more metabolically healthy diet by minimizing processed grains, added sugar, and other high-carb foods over time.

I know — we’ve heard it all before. However, it isn’t just what you eat but how you consume it that can impact your metabolic response. Here’s where it gets interesting.

“For example, if we pair a carb-rich apple with a handful of almonds, the added fat, protein, and fiber can help blunt the glucose response,” explains Kelley-Chew. “The order in which we eat matters, too — having fat or protein before carbs can help curb the blood sugar impact, and consuming vinegar or cinnamon before or with a meal may also lower the glucose response.”

Metabolism and glycemic variability 

According to Levels, your blood sugar levels continuously fluctuate — it’s called glycemic variability, and it’s pretty normal. However, the degree of variability can determine your long-term health. High levels can have short and long-term effects, so achieving peak metabolic health requires a low variance. 

Your diet plays a pivotal role. Eating processed foods that spike blood sugar levels will force your body to release more insulin to move excess glucose to your cells. A blood sugar crash and sudden drop in glucose levels will follow, which can cause poor mood, tiredness, and headaches. Prolonged high levels of variability could also lead to high blood pressure, weight gain, Type 2 diabetes, and other chronic health problems in the future. 

You can combat high levels of variability by eating foods that stabilize your blood sugar, increasing your protein, fats, and fiber intake, controlling your stress, getting adequate sleep and exercising more. Check out Chris Hemsworth’s 5-minute breathing exercise and how strength training can boost your metabolism if you struggle with inspiration.  And this is the best time to drink a protein shake

Improve metabolism: diet 

Glucose isn't everything. Micronutrients like vitamins, minerals, and antioxidants, are also important. “These essential dietary elements keep your body running optimally at a cellular level. Micronutrients are crucial links in chain reactions involving proteins, enzymes, and hormones that regulate every part of your body’s metabolism. If one of the links is weak or missing, the entire system can malfunction,” says Kelley-Chew. 

So, what sorts of foods are best? She recommends limiting foods that disrupt your metabolic function by choosing whole or minimally processed foods, avoiding added sugars, and minimizing refined grains like white bread or white rice. Instead, favor nutrient-dense fare — think organic, natural, and grass-fed where you can. I also don’t recommend calorie counting, here’s why

It doesn’t mean you can’t enjoy all foods, and your diet should feel enjoyable and balanced. Instead, gradual tweaks and improvements rather than a drastic overhaul can positively impact your metabolism and metabolic health in the long-run.

“Diet and metabolic health are highly individual. Your glucose reactions may be different than someone else’s, so while we don’t endorse a one-size-fits-all diet, we can identify nutrient-dense foods that lead to stable glucose in most people,” Kelley-Chew counters. “It’s a great place to start when building your metabolically friendly diet.”


If you’re keen to get more metabolically fit this year, check out what to eat before or after a workout and boost mood and calorie burn with this 15-minute walking workout to get you moving more. Also, this Lumen device tracks metabolism, and this smart ring offers fitness tracking, including your metabolism


Image of Lauren Kelley-Chew
Lauren Kelley-Chew

Lauren Kelley-Chew, MD is the head of clinical products at Levels (opens in new tab). Prior to Levels, Lauren led Strategy & BizOps at Verily Life Sciences and founded a Y Combinator-backed digital therapeutics start-up. Lauren graduated from medical school at UPenn, where she was a Gamble Scholar. 

Sam Hopes
Staff Fitness Writer

Sam Hopes is a level III fitness trainer, level II reiki practitioner, and resident fitness writer at Future PLC, the publisher of Tom's Guide. Having trained to work with mind and body, Sam is a big advocate of using mindfulness techniques in sport and fitness, and their impact on performance. She’s also passionate about the fundamentals of training and building sustainable training methods.  When she's writing up her experiences with the latest fitness tech, you’ll find her writing about nutrition, sleep, recovery, and workouts.