The Unexpected Way A Low Carb Diet Affects Your Life Expectancy

Every few years, a trendy low-carb diet emerges from the void. You might have been tempted to follow one of them in the past, enjoying the quick weight loss, only to feel the weight return once you begin eating bread again. Different low-carb diets emphasize different nutrients. Some low-carb diets can help control diabetes because they limit sugars that spike blood sugar. Many of these simple carbs lack fiber to help you feel full and instead swap more protein or fat to help you eat less. The keto diet restricts carbs to lower-carb fruits like berries or vegetables like broccoli and bell peppers. You'll focus on moderate protein while including foods high in fat. The paleo diet lets you have your fruits and vegetables but eliminates dairy, grains, beans, and more processed foods (per Iowa Clinic).

According to a 2018 article in The Lancet, your carb intake could influence your longevity. Following an extremely low-carb diet could take four years off your life expectancy. But it's not as much about the carbs as it is about your source of protein and fat.

A moderate carb intake has the highest longevity

The study followed more than 15,000 people over 25 years and looked at how their carbohydrate intake factored into how long they lived. People whose carb intake averaged between 50 and 55% of their daily calories lived the longest. Restricting carbs to less than 40% of their intake resulted in an increased mortality risk. But that doesn't mean you should switch to an all-pasta diet. A diet high in carbohydrates — more than 70% of your total calories — can also decrease your life expectancy.

The study also examined the types of foods people consumed, finding that low-carb diets with animal-derived fats and proteins (like meat) were linked to higher mortality, while plant-based low-carb diets (including vegetables, nuts, and whole grains) were associated with lower mortality. Overall, maintaining a balanced carbohydrate intake, along with choosing plant-based sources over animal-based ones, may contribute to a longer and healthier life.

"On an 'average' 2,000 kcal-a-day intake, a diet of 30% calories from carbs equates to only 150g a day, with sugars (natural or 'added') contributing around 50g of that total. With a mere 100g of complex carb a day to play with, a lower intake of cereals, grains, and starchy vegetables is inevitable," Catherine Collins, a dietician from the UK's National Health Service told CNN.

Look for healthier food sources

You don't have to give up your low-carb lifestyle if you like the way it feels. To secure the health benefits of low-carb eating, it's about paying attention to the protein and fat sources you're eating. Rather than eat protein from animal sources, you can also incorporate edamame and soy into your diet for some plant-based protein. Some of the animal food sources are also high in saturated fats, so including more avocados, nuts, and seeds will give you heart-healthy unsaturated fat (per Healthline).

You'll also want to take a look at your carb sources. Complex carbs like oatmeal will help keep you full because they don't get digested as quickly as simple carbs. It's also a good idea to consume carbs with little processing for their key vitamins, minerals, and antioxidants. Some ultra-processed baked snacks lack nutrition but can be high in salt, sugar, or fat (per Heart and Stroke Foundation of Canada).