Intermittent Fasting Plus Early Eating May Prevent Type 2 Diabetes

Individuals at increased risk of type 2 diabetes may be able to reduce their risk via a novel intervention combining intermittent fasting (IF) with early time-restricted eating, indicate the results of a randomized controlled trial.

The study involved more than 200 individuals randomized to one of three groups: eat only in the morning (from 8:00 AM to noon) followed by 20 hours of fasting 3 days per week and eat as desired on the other days; daily calorie restriction to 70% of requirements; or standard weight loss advice.

The IF plus early time-restricted eating intervention was associated with a significant improvement in a key measure of glucose control versus calorie restriction at 6 months, while both interventions were linked to benefits in terms of cardiovascular risk markers and body composition, compared with the standard weight loss advice.

However, the research, published in Nature Medicine, showed that the additional benefit of IF plus early time-restricted eating did not persist, and less than half of participants were still following the plan at 18 months, compared with almost 80% of those in the calorie-restriction group.

"Following a time-restricted, IF diet could help lower the chances of developing type 2 diabetes," said senior author Leonie K. Heilbronn, PhD, University of Adelaide, South Australia, in a press release.

This is "the largest study in the world to date, and the first powered to assess how the body processes and uses glucose after eating a meal," with the latter being a better indicator of diabetes risk than a fasting glucose test, added first author Xiao Tong Teong, a PhD student, also at the University of Adelaide.

"The results of this study add to the growing body of evidence to indicate that meal timing and fasting advice extends the health benefits of a restricted-calorie diet, independently from weight loss, and this may be influential in clinical practice," Teong added.

Adherence Difficult to IF Plus Early Time-Restricted Eating

Asked to comment, Krista Varady, PhD, said that the study design "would have been stronger if the time-restricted eating and IF interventions were separated" and compared.

"Time-restricted eating has been shown to naturally reduce calorie intake by 300-500 kcal/day," she told Medscape Medical News, "so I'm not sure why the investigators chose to combine [it] with IF. It...defeats the point of time-restricted eating."

Varady, who recently coauthored a review of the clinical application of intermittent fasting for weight loss, also doubted whether individuals would adhere to combined early time-restricted eating and IF. "In all honesty, I don't think anyone would follow this diet for very long," she said.

She added that the feasibility of this particular approach is "very questionable. In general, people don't like diets that require them to skip dinner with family/friends on multiple days of the week," explained Varady, professor of nutrition at the University of Illinois, Chicago.  "These regimens make social eating very difficult, which results in high attrition."

"Indeed, evidence from a recent large-scale observational study of nearly 800,000 adults shows that Americans who engage in time-restricted eating placed their eating window in the afternoon or evening," she noted.

Varady therefore suggested that future trials should test "more feasible time-restricted eating approaches," such as those with later eating windows and without "vigilant calorie monitoring."

"These types of diets are much easier to follow and are more likely to produce lasting weight and glycemic control in people with obesity and prediabetes," she observed.

A Novel Way to Cut Calories? 

The Australian authors say there is growing interest in extending the established health benefits of calorie restriction through new approaches such as timing of meals and prolonged fasting, with IF — defined as fasting interspersed with days of ad libitum eating — gaining in popularity as an alternative to simple calorie restriction.

Time-restricted eating, which emphasizes shorter daily eating windows in alignment with circadian rhythms, has also become popular in recent years, although the authors acknowledge that current evidence suggests any benefits over calorie restriction alone in terms of body composition, blood lipids, or glucose parameters are small.

To examine the combination of IF plus early time-restricted eating, in the direct trial, the team recruited individuals aged 35-75 years who had a score of at least 12 on the Australian Type 2 Diabetes Risk Assessment Tool but did not have a diagnosis of diabetes and had stable weight for more than 6 months prior to study entry.

The participants were randomized to one of three groups:IF plus early time-restricted eating, which allowed consumption of 30% of calculated baseline energy requirements between 8:00 AM and midday, followed by a 20-hour fast from midday on 3 nonconsecutive days per week. They consumed their regular diet on nonfasting days.Calorie restriction, where they consumed 70% of daily calculated baseline energy requirements each day and were given rotating menu plans, but no specific mealtimes.Standard care, where they were given a booklet on current guidelines, with no counseling or meal replacement.

There were clinic visits every 2 weeks for the first 6 months of follow-up, and then monthly visits for 12 months. The two intervention groups had one-on-one diet counseling for the first 6 months. All groups were instructed to maintain their usual physical activity levels.

Two hundred and nine individuals were enrolled between September 26, 2018 and May 4, 2020. Their mean age was 58 years, and 57% were women. Mean body mass index (BMI) was 34.8 kg/m².

In all, 40.7% of participants were allocated to IF plus early time-restricted eating, 39.7% to calorie restriction, and the remaining 19.6% to standard care.

The results showed that IF plus early time-restricted eating was associated with a significantly greater improvement in the primary outcome of postprandial glucose area under the curve (AUC) at month 6 compared with calorie restriction, at –10.1 mg/dL/min versus –3.6 mg/dL/min (P = .03).

"To our knowledge, no [prior] studies have been powered for postprandial assessments of glycemia, which are better indicators of diabetes risk than fasting assessment," the authors underline.

IF plus early time-restricted eating was also associated with greater reductions in postprandial insulin AUC versus calorie restriction at 6 months (P = .04). However, the differences between the IF plus early time-restricted eating and calorie restriction groups for postmeal insulin did not remain significant at 18 months of follow-up.

Both IF plus early time-restricted eating and calorie restriction were associated with greater reductions in A1c levels at 6 months versus standard care, but there was no significant difference between the two active interventions (P = .46).

Both interventions were also associated with improvements in markers of cardiovascular risk versus standard care, such as systolic blood pressure at 2 months, diastolic blood pressure at 6 months, and fasting triglycerides at both time points, with no significant differences between the two intervention groups.

IF plus early time-restricted eating and calorie restriction were also both associated with greater reductions in BMI and fat mass in the first 6 months, as well as in waist circumference.

Calorie Restriction Easier to Stick to, Less Likely to Cause Fatigue 

When offered the chance to modify their diet plan at 6 months, 46% of participants in the IF plus early time-restricted eating group said they would maintain 3 days of restrictions per week, while 51% chose to reduce the restrictions to 2 days per week.

In contrast, 97% of those who completed the calorie-restriction plan indicated they would continue with their current diet plan.

At 18 months, 42% of participants in the IF plus early time-restricted eating group said they still undertook 2 to 3 days of restrictions per week, while 78% of those assigned to calorie restriction reported that they followed a calorie-restricted diet.

Fatigue was more common with IF plus early time-restricted eating, reported by 56% of participants versus 37% of those following calorie restriction, and 35% of those in the standard care group at 6 months. Headaches and constipation were more common in the intervention groups than with standard care.

The study was supported by a National Health and Medical Research Council Project Grant, an Australian Government Research Training Program Scholarship from the University of Adelaide, and a Diabetes Australia Research Program Grant.

No relevant financial relationships were declared.

Nat Med. Published online April 6, 2023. Full text

Some Diets Better Than Others for Heart Protection

A new analysis of randomized trials suggests that the Mediterranean diet and low-fat diets probably reduce the risk of death and nonfatal myocardial infarction (MI) in adults at increased risk for cardiovascular disease (CVD), while the Mediterranean diet also likely reduces the risk of stroke.

Five other popular diets appeared to have little or no benefit with regard to these outcomes.

"These findings with data presentations are extremely important for patients who are skeptical about the desirability of diet change," write the authors, led by Giorgio Karam, with University of Manitoba, Winnipeg, Canada.

The results were published online March 29 in The BMJ.

Dietary guidelines recommend various diets along with physical activity or other cointerventions for adults at increased CVD risk, but they are often based on low-certainty evidence from nonrandomized studies and on surrogate outcomes.

Several meta-analyses of randomized controlled trials with mortality and major CV outcomes have reported benefits of some dietary programs, but those studies did not use network meta-analysis to give absolute estimates and certainty of estimates for adults at intermediate and high risk, the authors note.

For this study, Karam and colleagues conducted a comprehensive systematic review and network meta-analysis in which they compared the effects of seven popular structured diets on mortality and CVD events for adults with CVD or CVD risk factors.

The seven diet plans were the Mediterranean, low fat, very low fat, modified fat, combined low fat and low sodium, Ornish, and Pritikin diets. Data for the analysis came from 40 randomized controlled trials that involved 35,548 participants who were followed for an average of 3 years.

There was evidence of "moderate" certainty that the Mediterranean diet was superior to minimal intervention for all-cause mortality (odds ratio [OR], 0.72), CV mortality (OR, 0.55), stroke (OR, 0.65), and nonfatal MI (OR, 0.48).

On an absolute basis (per 1000 over 5 years), the Mediterranean diet let to 17 fewer deaths from any cause, 13 fewer CV deaths, seven fewer strokes, and 17 fewer nonfatal MIs.

There was evidence of moderate certainty that a low-fat diet was superior to minimal intervention for prevention of all-cause mortality (OR, 0.84; nine fewer deaths per 1000) and nonfatal MI (OR, 0.77; seven fewer deaths per 1000). The low-fat diet had little to no benefit with regard to stroke reduction.

The Mediterranean diet was not "convincingly" superior to a low-fat diet for mortality or nonfatal MI, the authors note.

The absolute effects for the Mediterranean and low-fat diets were more pronounced in adults at high CVD risk. With the Mediterranean diet, there were 36 fewer all-cause deaths and 39 fewer CV deaths per 1000 over 5 years.

The five other dietary programs generally had "little or no benefit" compared with minimal intervention. The evidence was of low to moderate certainty.

The studies did not provide enough data to gauge the impact of the diets on angina, heart failure, peripheral vascular events, and atrial fibrillation.

The researchers say that strengths of their analysis include a comprehensive review and thorough literature search and a rigorous assessment of study bias. In addition, the researchers adhered to recognized GRADE methods for assessing the certainty of estimates.

Limitations of their work include not being able to measure adherence to dietary programs and the possibility that some of the benefits may have been due to other factors, such as drug treatment and support for quitting smoking.

The study had no specific funding. The authors have disclosed no relevant financial relationships. 

BMJ. Published online March 29, 2023. Full text

Intermittent fasting may change how your DNA is expressed

Mice who only ate at specific times of the day experienced “profound” changes in genetic expression, leading to health benefits like reduced risk of obesity and inflammation, new research found.

To an extent, it’s not about  what you eat as much as when you eat it — so says recent research that sheds new light on the benefits of intermittent fasting. 

The study, published Tuesday in journal Cell Metabolism, found that mice fed only during certain blocks of time experienced “profound” changes in gene expression. Nearly 80 per cent of all genes were impacted in some way, the paper reads.

The changes resulted in a plethora of health benefits, the authors wrote, including: improved blood sugar regulation, decreased risk of obesity and even a reversal of certain hallmarks of ageing.
You can think of a gene as the blueprint for a specific protein, written in DNA. When a gene is expressed, the blueprint is converted into its protein product by cellular machinery. Because proteins are responsible for most cellular functions from fat metabolism to immune response, even slight changes in gene expression could leave a massive impact.

According to the research, restricting when mice could eat reshaped when and to what extent certain genes were expressed — for example, some organs learned to switch on the genes for regulating blood sugar when it came feeding time, and to repress them when it was time to fast.

The researchers say their findings opened the door for further research into how dietary interventions might impact our genes and what this means for those suffering from issues like diabetes, heart disease and cancer.

What is time-restricted eating?

Shaunak Deota, first author of the study and a post-doctoral fellow at the Salk Institute for Biological Studies in San Diego, explained time-restricted eating as “eating consistently in a narrow window of 8 to 10 hours” when one is most active and fasting the remainder of the day. Intermittent fasting is a form of this practice, he said.

By feeding and fasting at the same time every day, we are reinforcing a biological rhythm in our bodies, Deota said: “Our body is getting the food at the same time every day, so all our organ systems know when the food is going to come and they’re prepared for it.”

Previous studies have shown that time-restricted eating may reduce the risk of obesity and diabetes, help to improve cardiovascular health, provide benefits for gut function and cardiovascular health and more.

Deota’s research now contributes, to his knowledge, the first “holistic” look at how time-restricted eating impacts the body as a system.

To achieve their results, the researchers put two groups of mice on the same high-calorie diet. One group was only allowed to eat during a nine-hour window when they were most active. The other could feed whenever they wanted.

After seven weeks, the mice on a time-restricted diet gained less weight than their counterparts, despite eating the same amount of food. 

The researchers then killed 48 of the mice — 24 from each group — to investigate the diet’s impact on the body. They sacrificed two mice from each group every two hours over a 24-hour period, noting how their organ systems changed over time.

How time-restricted eating changes the body

After studying the mouse organs, Deota and his team made a “pretty surprising” discovery; mice on the time-restricted diet had synchronized their gene expression with their feeding schedules.

“That is important because these genes will get translated into proteins,” Deota said. “Those proteins are helping our body to anticipate that there is food coming.”

According to their paper, roughly 70 per cent of all mouse genes fell into rhythm with the feeding schedule. Come mealtime, individual organs could promote genes in charge of nutrient metabolism while suppressing those responsible for inflammatory signalling and immune activation.

Moreover, the scientists found the diet reversed several hallmarks of aging, leading to reduced inflammation, increased cellular housekeeping, improved RNA and protein balance and more.

“Molecularly speaking, we saw a lot of pathways which are activated by (the time-restricted diet) in multiple organ systems. And a lot of these pathways actually have been implicated in improving health and leading to a longer, healthy life,” Deota said.

The limitations

All that being said, we need to remember these results were seen in mice, not humans — we’re still a long way off from demonstrating the same phenomenon happens in people, said Dani Renouf, a registered dietitian at St. Paul’s Hospital in Vancouver. For now, these results represent a “wonderful start to a conversation.”

“We’re just prototyping at this point because we’re using animal models and looking at things on a cellular level,” she said. “In order to now make conclusions in human beings, we need to take several steps before we can definitively do that with time restricted-eating.”

Renouf also noted the experiments took place in a tightly controlled environment. Real life is messy and chaotic, she said, and will likely influence results.

On the flip side, Deota believes “most of these benefits can be translated to humans” because his lab’s findings line up with what clinical studies into time-restricted eating have discovered.

Lose Your Weight and Stomach Fat Fast With These 10 Diet Life Hacks

Ready to hear the dirty little secret no one tells you about how to lose stomach fat?

The secret is — you can’t. At least, not the way that you think.

Studies show that blasting your abs with tons of crunches won’t trim your belly fat, just like doing curls won’t give you tighter arms and squats won’t give you leaner legs.

Spot reducing fat or picking and choosing where you’d like to lose fat on your body, is a complete and utter myth.

The only way to get a leaner midsection is to shed fat from your entire body. To do this, you’ll need the right combination of diet strategy and exercise — something you can stick to long enough for your body to start tapping into the fat stores in your belly.

There are as many approaches to losing weight as there are people on this planet, but no matter who you are, here are 10 diet hacks to keep you on track as you lean down in your quest for a flat stomach.

1. Create a Consistent Calorie Deficit

Eating the right number of calories on a daily basis is the number one driver of fat loss. Don’t let the low-fat or low-carb gurus fool you!

What’s the right number of calories?

Well, a calorie is a unit of energy that our bodies primarily derive from food. Every day, we burn a certain number of calories depending on our size, age, gender, and activity levels. To burn fat, which is to say, to force our bodies to tap into our fat reserves and use them for energy instead of food, we need to eat fewer calories than we burn in a day.

The key is not to overcomplicate your diet by demonizing specific food groups or macronutrients. Aim for a deficit of about 500 calories per day. The easiest method to calculate this is to multiply by 12 calories per pound of bodyweight and eat that many calories every day. If you do nothing else on this list except consistently hit your daily calorie target, you WILL lose weight.

2. Eat Slower and Be Patient

Eating fewer calories to lose weight is really simple, but that’s not to say that it’s easy.Forcing your body to burn its fat stores for energy is an uncomfortable process that might leave you feeling drained and with less energy, while getting used to smaller meals may leave you feeling hungry at first.

One great workaround is to eat slower, chew more, and be patient. There is evidence to support the idea that eating more slowly can increase how satisfied and full some people feel after a meal, and decrease your desire to eat more. It simply takes time for your stomach to communicate to your brain that it’s full and satisfied! If you eat quickly, you might bypass this signal and wind up eating more than you really needed to feel full.

Not only that, but it takes a solid 2 to 3 hours for your body to convert food you’ve just eaten into actual, usable energy. Even after eating a large meal while dieting, you may still feel hungry, but that doesn’t mean you need to eat more.

If you’re patient enough and allow your body to do its work, you’ll usually feel a jolt of energy a few hours after eating.

3. Eat More Protein

If you hit the right number of calories every day, you’ll be well on your way toward losing your belly, regardless of the overall makeup of your diet.However, there is lots of evidence to suggest that people interested in fat loss should consider a diet high in protein.

People who eat more protein are generally more satisfied and tend to eat fewer calories overall. Plus, a healthy dose of protein every day will help you preserve more muscle mass and encourage your body to lose more fat.

Your protein needs will vary depending on your gender and activity levels, but most people should shoot for at least 40 to 50 grams of protein every day.

4. Delay Your First Meal

Ever heard of intermittent fasting? It’s an eating style wherein you drastically reduce your eating window during the day while remaining fasted the rest of the time. For example, you might be “allowed” to eat for 8 hours, from noon to 8pm, while the rest of the time you only drink water.

The health benefits of fasting are vast and go far beyond weight loss and include boosts in mood, energy, focus, longevity, and more. However, you needn’t jump right into long, extended fasts, though they can be extremely effective.

Try pushing your first meal back just a few hours after you wake up. You’ll likely trigger more fat burning than you would by eating right away, and surprisingly, you’ll probably be a lot less hungry eating nothing than you would after eating a small breakfast.

Even mild fasting can dramatically decrease your overall appetite and calorie intake throughout the day.

5. Work Your Core

I know I said you can’t force your body to lose stomach fat, but that doesn’t mean you shouldn’t be prepared for the day that it does!

Work your abdominal and core muscles 2 to 3 times per week to build strength in your midsection. As you begin to lose fat, you’ll discover better tone and definition in that area than if you ignored it.

What are the best core exercises? Leave the crunches on the bench and try some more challenging moves like:

· Hanging leg raises

· Planks

· Reverse sit ups

· Incline sit ups

· Ab wheel roll outs

You don’t need much, just 2 to 3 sets of 20 reps or so a few times per week should be plenty to build those abs and prepare them for their big reveal.

6. Do the Right Kind of Cardio

Believe it or not, exercise is completely optional when it comes to losing weight. If you eat the right number of calories, the fat will come off regardless.

However, it will be much easier to create your consistent calorie deficit if you’re active and burning extra calories at least a few times per week. Plus, exercising is a whole lot better for your health that not exercising.

Cardio can definitely help! But you’ll have a few choices for how to go about it:

• LISS (Low Intensity Steady State): Going for a long walk or light jog would be considered low intensity cardio. The benefits of this kind of exercise are that you’ll burn calories without taxing your body too badly and driving up your appetite. The downside? It can be kind of boring and lengthy, therefore difficult to incorporate on a consistent basis as a result.
• HISS (High Intensity Steady State): Think going for a long run. The plus side of HISS is that you’ll burn more calories a lot faster when compared to LISS, however these workouts are more draining and difficult to recover from. You may find yourself extremely hungry as a result of the exertion.
• HIIT (High Intensity Interval Training): HIIT refers to short bursts of intense exercise followed by stretches of rest or long intensity work. Imagine walking on a treadmill and occasionally working in high-speed sprints, or doing a circuit of pushups, air squats, lunges, etc. with rest intervals worked in. These workouts burn a ton of calories quickly and dramatically improve your conditioning, but they can also be difficult for your body to recover from and can drive up your appetite.

Each form of cardio has its place, but for fat loss, I’d recommend sticking mostly with LISS or HIIT workouts to burn extra calories a few times per week.

7. Eat More Filling Foods

Again, hitting a calorie target sounds simple, but that doesn’t make it easy!

If you find you’re consistently getting hungry throughout the day when trying to stick to a diet, you may need to change up your food choices.

Sure, you could technically lose weight by eating 1200 calories of Doritos every day, though I wouldn’t recommend it!Your best bet will be to eat lots of nutrient rich foods that satiate your body and take time to digest.

Simple carbs (white bread, sugar, etc.) are unquestionably delicious but offer little nutritional value, so your body churns through them quickly. They might briefly fill your stomach, but they won’t leave you satisfied for long.

Complex carbs (oatmeal, brown rice, sweet potatoes) and lean proteins (chicken, turkey) will keep you full for longer and better fuel your body for any workouts you might incorporate.

8. Utilise Strategic Refeeds and Diet Breaks

You likely won’t need these strategies when you first begin your diet, but as you start to see results and get to a lower body fat percentage, you might find your body needs a break every now and then.

After all, burning your own fat for energy is difficult on the body and mind. Long-term adherence to the diet is a lot more important than getting results as fast as possible.

Consider adding in one refeed day per week, where you eat an additional 500 calories or so (usually complex carbs). This will help restore your body’s energy and promote a healthy metabolism.

You can also take a 2 to 4 week diet break, where you eat your body’s maintenance calories (around bodyweight times 15 calories per day) and allow yourself to recover and rejuvenate.

Funny enough, you may find that eating more actually encourages your body to shed some of the fat it’s been desperately clinging to. Studies show that people who take strategic breaks from dieting now and then have better long-term fat loss results.

9. Get More Sleep

So much of adhering to a fat loss diet comes down to willpower and mental focus.

Know what the number one killer of willpower is? A lack of sleep.

Sleep deprivation can cause chaos with your hormonal balance and ability to regulate your appetite, but more importantly, it can leave you with very little self-control. People who don’t sleep enough find themselves snacking more and overeating more frequently.

Blue light from phones, computers, and TVs, for example, is known to disrupt sleep patterns. Opt for a book before bed if you’re having trouble getting to sleep on time.

10. Track Everything

An extra bite of your friend’s dessert here, a quick snack there, and another dollop of sauce or oil on your plate… It all adds up, and those extra calories can easily derail your diet if you’re not careful.

To be sure you’re hitting your calorie goal every day, it’s best to track everything, even if you’re only using your best estimation (though calorie counters can help, too).

Tracking meals is one thing, but for the best results you’ll want to write down every single thing you take into your body including sauce, oil, sides, snacks, drinks, and more.

Forgetting about that 300 to 500 extra calories you had during the day will be the difference between losing belly fat fast, and not.

The Bottom Line

I wish there was an easy way to quickly lose fat from your belly, believe me!

What more people need to understand is that, although targeted fat loss is impossible, fat doesn’t come off of your body completely evenly, either.

For many people, especially men, the stomach is their body’s absolute favorite place to store fat. You may need to lose a significant amount of weight before your body is ready to start tapping into its belly stores.

Remember to set your calorie target and focus on hitting it every single day. Exercising, getting lots of protein, and incorporate tricks to stay motivated can really help, but the energy deficit is the primary driver and fat loss and should be your main priority.

You’ll likely need to stick with the plan for a long time before that stomach completely flattens out.

Reference

		J Strength Cond Res.: The effect of abdominal exercise on abdominal fat
		Science Direct: Calories do count
		Science Direct: Slower eating rate reduces the food intake of men, but not women
		The American Journal of Clinical Nutrition: A high-protein diet induces sustained reductions in appetite …
		Trusty Spotter: I tried my first 24 hour fast. Here’s what happened.
		Science Daily: Taking a break from dieting may improve weight loss
		WebMD: Sleep and Weight Gain