Category: Diabetes

Whether you are a night owl or an early bird influences your risk of type 2 diabetes and heart disease.

People who sleep late and are active later in the day are more likely to develop type 2 diabetes and heart disease than those who wake up early.

A person’s chronotype has an impact on a number of diseases such as metabolic syndrome (a condition that increases the risk of type 2 diabetes, cardiovascular disease, and stroke).

Chronotype is related to circadian rhythms and is the body’s natural tendency to sleep or stay alert over a 24-hour period.

Early chronotypes are those individuals who prefer to get up early and do their activity in the morning, whereas late chronotypes are those who stay up late and are active later in the day.

A study suggests that our body metabolism and preferred source of energy are influenced by the sleep–wake cycle.

Our body uses fat as a fuel, but the efficiency of turning fat to energy is lower in late chronotypes.

The accumulation of fat puts late chronotypes at higher risk of cardiovascular disease and type 2 diabetes.

People who stay active during late hours burn less fat even during exercise, whereas early risers tend to use more fat for energy either at rest or physical activity.

Night owls vs. early birds

For this study, participants based on their chronotype were divided to two groups.

Their body composition (percentage of fat, muscle, and bone), body mass, and insulin sensitivity was examined for carbohydrate and fat metabolism.

Participants followed a standardised diet and fasted overnight while their activity patterns were tracked during the day for a week.

They also did two 15-minute sessions of moderate and high intensity exercise.

The results showed that those who were ‘night owls’ burned less fat for energy during exercise and rest than ‘early birds’.

They were also insulin resistant, meaning their body does not react well to blood glucose.

Therefore their bodies need more glucose and so they prefer carbohydrates over fats as a source of energy, which puts them at higher risk of developing diabetes and obesity.

Professor Steven Malin, the study’s first author, said:

“The differences in fat metabolism between ‘early birds’ and ‘night owls’ shows that our body’s circadian rhythm (wake/sleep cycle) could affect how our bodies use insulin.

A sensitive or impaired ability to respond to the insulin hormone has major implications for our health.

This observation advances our understanding of how our body’s circadian rhythms impact our health.

Because chronotype appears to impact our metabolism and hormone action, we suggest that chronotype could be used as a factor to predict an individual’s disease risk.

We also found that early birds are more physically active and have higher fitness levels than night owls who are more sedentary throughout the day.

Further research is needed to examine the link between chronotype, exercise and metabolic adaptation to identify whether exercising earlier in the day has greater health benefits.”

The study was published in the journal Experimental Physiology (Malin et al., 2022).

A carb diet that can help people with type 2 diabetes and those with prediabetes by lowering blood sugar levels.

Past studies have suggested that low-carbohydrate diets are as effective as low-fat diets for weight loss and reducing risk factors for cardiovascular disease.

Yet little evidence supports the effects of low-carb diets on haemoglobin A1c (HbA1c) in those with prediabetes and unmedicated diabetes.

Haemoglobin is the part of red blood cells that carries oxygen to the body and glycohaemoglobin or HbA1c is a type of haemoglobin containing sugar found in the blood.

A study provides evidence that eating a low-carbohydrate diet would reduce HbA1c and lower blood sugar levels, important factors for preventing and treating type 2 diabetes.

Participants in this study were individuals with prediabetes or untreated diabetes between 40 and 70 years of age.

They were divided into two groups; one followed a diet containing less than 40g of carbohydrates per day and the other group went on with their usual diet for six months.

In the low-carb group, most calories came from protein and healthy fats such as nuts and olive oil that contain monounsaturated and polyunsaturated fats.

During this period, those on the low-carb diet lost 6 kg on average and had reductions in HbA1c of 0.23 percent and lower blood glucose levels than the usual diet group.

The drop in HbA1c levels is modest but clinically important, especially for those with prediabetes as their blood glucose levels are higher than normal but lower than people with diabetes.

Dr Kirsten Dorans, the study’s first author, said:

“The key message is that a low-carbohydrate diet, if maintained, might be a useful approach for preventing and treating Type 2 diabetes, though more research is needed.”

About diabetes

Diabetes is a condition where blood sugar is too high because the body doesn’t respond to insulin that regulates glucose levels.

Over 37 million American adults have type 2 diabetes, of which more than 8 million are undiagnosed.

More than 100 million American adults have prediabetes and 80 percent of those are unaware of their condition.

Diabetes has a big impact on people’s life and can damage the heart, eyes, blood vessels, nerves, and kidneys.

Symptoms include blurry vision, tingling and numbness in hands and feet, fatigue, ache, and pain.

Dr Dorans said:

“We already know that a low-carbohydrate diet is one dietary approach used among people who have Type 2 diabetes, but there is not as much evidence on effects of this diet on blood sugar in people with prediabetes.

Future work could be done to see if this dietary approach may be an alternative approach for Type 2 diabetes prevention.”

The study was published in JAMA Network Open (Dorans et al., 2022).