In recent years, intermittent fasting has garnered attention as a powerful tool to improve metabolic health and potentially lower the risk of developing type 2 diabetes.
A new study published in Nature Medicine in April 2023 adds a twist to this approach, combining intermittent fasting with early time-restricted eating to maximize its benefits.
Intermittent Fasting and Early Time-Restricted Eating
Both intermittent fasting and time-restricted eating focus on when you eat, rather than what you eat. They also aren’t necessarily about restricting calorie intake, but rather about controlling the timing of your calorie intake.
Intermittent fasting involves alternating periods of eating and fasting. For example, this might involve eating nothing (or nearly nothing) for one day each week, and eating normally the rest of the week.
Early time-restricted eating is based on a similar idea, focusing on consuming all your daily calories within a shortened time window (between 8am and 2pm, for example) and then eating nothing else outside of that time window.
The idea here is to give your body a break from digesting food, allowing it to focus on cellular repair and other essential processes.
The Study: Intermittent Fasting Plus Early Time-Restricted Eating
The recent study in Nature Medicine explored a novel approach called intermittent fasting plus early time-restricted eating (iTRE). The researchers randomly assigned 209 adults at an increased risk of developing type 2 diabetes to one of three groups: iTRE, calorie restriction (CR), or standard care.
The iTRE group followed a plan that involved consuming 30% of their daily energy requirements between 8am and 12pm on three nonconsecutive days per week, followed by a 20-hour fasting period. On other days, they ate ad libitum (at liberty, however they wanted).
The calorie restriction group reduced their daily energy intake to 70% of their energy requirements, without any specific time restrictions. The standard care group received a weight loss booklet.
The trial lasted for 6 months, with an additional 12-month follow-up.
The study found that iTRE led to greater improvements in glucose tolerance compared to calorie restriction alone after 6 months.
However, these differences were no longer apparent at the 18-month follow-up.
Adverse events reported were generally mild and transient, with reports of fatigue being higher in the iTRE group compared to the other groups.
Constipation and headache were reported more in both the iTRE and CR groups compared to the standard care group.
Applying iTRE in Daily Life
If you are living with type 2 diabetes or prediabetes and are interested in trying this dietary approach, discuss your plans with your doctor to ensure it’s suitable for your individual needs.
- Gradually adjust your eating window: If you’re new to intermittent fasting, start with a wider eating window and gradually work your way to a narrower window as your body adjusts.
- Choose nutrient-dense foods: When you are in your eating window, it is very important to focus on consuming nutrient-dense, whole foods, such as fruits, vegetables, lean proteins, and healthy fats, to ensure you’re getting the necessary nutrients.
- Stay hydrated: Drinking water throughout the day, especially during fasting periods, can help control hunger and maintain hydration.
- Listen to your body: Fasting can potentially lead to symptoms such as dizziness, excessive fatigue, or loss of consciousness. Do not ignore these symptoms and contact your doctor immediately if you experience any concerning symptoms.
Intermittent fasting combined with early time-restricted eating offers a promising strategy for improving glucose metabolism in adults at risk of developing type 2 diabetes.
But when health conditions are involved, approach any dietary change with caution and discuss it with a healthcare professional before starting.
This new study adds additional insights to the growing list of benefits associated with meal timing and fasting for metabolic health, but further research is needed to fully understand the long-term effects of this approach.