Intermittent fasting has been around for a long time. But the eating plan that switches between fasting [not eating'] and eating on a set schedule, really took off in the early 2000s thanks to books, articles and documentaries highlighting the diet. By 2018, intermittent fasting got a boost due to celebrities like Jennifer Aniston and Hugh Jackman sharing success stories.

“They've heard people do well with it. They've seen some celebrity or a social media person say it's the thing that's helped them. Maybe it could,” says Nicole O’Neill, a registered dietitian with OSF HealthCare.

While many people have found intermittent fasting works, it’s not for everyone. O’Neill has consulted many people in the past 11 years who’ve tried using an eating schedule.  

“In my years as a dietitian, I’ve had two patients use intermittent fasting successfully [losing weight],” she says. “Everybody else, it's a variation or a no-go. It just really depends on the person. That’s why it's important to work with a dietitian to determine if it will work for you or not.” 

O’Neill adds that the emergence of weight loss drugs like GLP-1 medications have replaced the intermittent fasting diet for some.

There are many types of intermittent fasting methods, including the following:

16:8 – fasting for 16 hours and eating during an eight-hour window (for example, noon to 8 p.m.)

14:10 – a more normal approach with a 14-hour fast and a 10-hour eating window

5:2 – eating normally five days per week and consuming a significantly reduced calorie intake on two non-consecutive days

Before starting an intermittent fasting plan, O’Neill says it’s important to understand the benefits and drawbacks. “If intermittent fasting works for you, it’s an easy way to restrict your calories,” she says. “You're only going to eat twice during the day. And then you have that calorie deficit. And then you have weight loss.”

The cons of going long periods of time without eating include an increase in anxiety, fatigue, daytime sleepiness and even brain fog – not finishing words, thoughts or even tasks. Other potential issues are not getting enough protein, fiber, vitamins and minerals. 

Not for everyone 

O’Neill recommends eating two to three hours after waking up to help maintain energy levels and establish a consistent eating pattern.

“For some people, skipping breakfast is not going to work,” she says. “If they try to do intermittent fasting and wait until noon, they become so overly hungry that by the time they do get to their eight-hour eating window, they are out of control. They've eaten more calories than they would have if they would have had breakfast, lunch and dinner.”

O’Neill says if you have Type 1 diabetes, are pregnant, breastfeeding or under the age of 18, intermittent fasting is not recommended.

The bottom line, O’Neill says, is it won’t hurt to try intermittent fasting with guidance from a medical provider. It might just take some time to find the right method that works for you. A lot of it depends on your personality, lifestyle and other obligations.

“Any diet is worth trying because there are so many out there and we’re just individuals who need something specific for ourselves,” she says. 
 

Interview Clips 

Diabetes: a recap

Aminat Ogun, MD, a family medicine physician at OSF HealthCare, recaps Types 1 and 2 diabetes and where Type 1.5 fits in:

• Type 1: Dr. Ogun says the body’s immune system attacks insulin-producing cells in the pancreas.
  
  “Insulin is a hormone that brings glucose from food from the blood to the body’s cells for energy. So in Type 1 diabetes, the pancreas isn’t producing insulin,” Dr. Ogun explains. “This type of diabetes is usually seen in childhood and adolescence. It’s sudden onset. Symptoms are increased urination, increased thirst, weight loss and blurry vision. A lot of these people are dependent on insulin shots.”
   
• Type 2: The pancreas is producing insulin, but the body doesn’t recognize it. Dr. Ogun says these patients are typically age 40 and up, and the disease has a gradual onset.
  
  “Management is lifestyle modifications, like a healthy diet and physical activity,” Dr. Ogun says. “And there are medications to help control blood sugar like Metformin and Jardiance®, plus insulin shots.”
   
• Type 1.5: This is also called latent autoimmune diabetes in adults (LADA).
  
  “It’s a slow progressing form of Type 1 diabetes. It’s autoimmune like Type 1, but it’s usually seen in adults,” Dr. Ogun says. Symptoms are similar to Type 2 diabetes: fatigue, nausea and vomiting. Or, Dr. Ogun says some people may have little to no symptoms.

More on Type 1.5

So, if Type 1.5 diabetes can mimic Types 1 and 2, how do providers pin down a diagnosis?

Dr. Ogun says it’s something providers are learning more about and getting better at. She says providers will take a blood sample to look at your blood glucose and antibodies. Providers can also sample your blood or urine to look at your C-peptide level. C-peptide is a byproduct of insulin production, and if it’s low it’s cause for concern.

Treatment is similar to Type 2 diabetes: oral medication or an injectable GLP-1 medication like Ozempic®.

“But eventually once the autoimmune destruction happens, the person will need regular insulin,” Dr. Ogun says. “One good thing is that if you are aware the person might have Type 1.5, starting insulin earlier is a little bit better. Maybe that can preserve some of the cells in the pancreas and preserve some pancreas function.”

Shoring up your diet and exercise can also help.

Prevention

Dr. Ogun says since Type 1.5 diabetes is an autoimmune disease, there’s no bonafide way to prevent it. She adds there is a genetic component, meaning a child of someone with Type 1.5 is at a higher risk to get in themselves.

But, Dr. Ogun says sometimes education can be the best prevention. She says she’s happy Lance Bass has spoken out. Bass is active, fit and has diabetes – a sign that it can happen to anyone, and you should be aware of the disease.

Learn more

Read more about preventing and managing diabetes on the OSF HealthCare website.

Interview clips

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There's no magic weight loss drug

For those who don’t enjoy sleeping with what looks like the equivalent of a MiG fighter pilot mask, there’s possible relief with new medication approved to treat sleep apnea.

Sleep apnea is a disorder in which the airway either closes off completely or becomes so narrowed that breathing repeatedly stops and starts during sleep, often causing brief awakenings that disrupt restful sleep. A common treatment includes wearing a CPAP, or continuous positive airway pressure, mask to deliver air pressure into the airways to keep them open.

But now there’s a new option. The FDA recently approved tirzepatide (Zepbound) for adults with obesity and moderate-to-severe obstructive sleep apnea (OSA). The drug is typically prescribed for type 2 diabetes and is among the class of drugs known as GLP-1 receptor agonists, meaning they work on hormones that control appetite and insulin levels and can help promote weight loss.

Sarah Zallek, MD, a neurologist and vice president and chief medical officer for OSF HealthCare St. Joseph Medical Center in Bloomington, Illinois, is also medical director of OSF Sleep in Peoria. Dr. Zallek calls the approval of Zepbound for treatment of sleep apnea a significant and important development. She points out there have been few new developments for the treatment of OSA, and this is the first medication.

Could this let some people ditch their CPAP machines? Dr. Zallek says if their sleep apnea is caused by obesity, potentially yes.

“So, if you’re wearing CPAP and you have weight-related sleep apnea, weight loss is a great idea. The approval of Zepbound (tirzepatide) is a new avenue for us to look for treating overweight or obesity and to treat sleep apnea.”

Dr. Zallek says for some people with weight-related apnea, losing about 10% or more of overall body weight can significantly reduce or eliminate the sleeping disorder.  However, she warns that with GLP-1 agonists, it’s important to maintain a healthy diet and exercise because the medication carries significant risk of muscle loss.

 “It's really important for people who are using GLP-1s to maintain adequate nutritional intake, particularly with high quality protein, and maintain exercise, so that they get muscle resistance exercise and build and maintain muscle.”

Treatment of sleep apnea with CPAP is still the gold standard. Dr. Zallek says if switching to Zepbound to address sleep apnea, a doctor should continue to monitor weight loss and then test again to see if a person’s airway has opened up.

“Keep using that treatment until you successfully lose weight and get rid of the sleep apnea. It's not time to stop the CPAP and switch to Zepbound, for example. To treat sleep apnea, it's time to continue what you're doing, approach weight loss and then see if the sleep apnea has resolved.”

Studies have shown that people who have lost weight with GLP-1 drugs, tend to regain the weight once they quit taking the medication. This is because GLP-1s mimic natural hormones that regulate blood sugar, slow digestion, and make you feel full. So, Dr. Zallek stresses the need for lifestyle changes regardless of the approach to treating sleep apnea.

Dr. Zallek is board certified in Lifestyle Medicine, which means she incorporates therapeutic lifestyle interventions to treat and reverse chronic conditions. That includes a whole-food, plant-predominant eating pattern, physical activity, restorative sleep, stress management, avoidance of risky substances and positive social connections.

It’s possible other GLP-1 drug makers for Wegovy, Ozempic or Mounjaro will seek similar approval for use as treatment of sleep apnea. But, Dr. Zallek says people also need to talk with their provider and weigh the side effects with the benefits. Some of the side effects of the GLP1s include nausea, vomiting, diarrhea, delayed gastric emptying, low blood sugar, fatigue, and more serious complications such as gallstone disease, and pancreatitis.

As they say in the ads, “Ask your doctor if it's right for you."

Dr. Sarah Zallek