Understanding time-restricted eating; repairing damaged blood vessels

Q: I’ve been following your guidelines for restricted eating times and improved nutrition, and have lost 12 pounds in the past six months. Now I see that a new study declares that time-restricted eating doesn’t help with weight loss. So is it smart to restrict the time I eat or not? — David M., New York

A: Where to start? Both groups in the Chinese study published in the New England Journal of Medicine ate the same significantly reduced amount of calories daily. That means the researchers eliminated the possibility of discovering if time-restricted eating may, in real-life situations, reduce the amount of food people eat — and therefore lead to increased weight loss.

The study only followed 139 obese people, and while everyone cut their calorie intake by 25%, the time-restricted group was allowed to eat only during an eight-hour window. There is some indication that folks who usually have breakfast at 7 a.m. and dinner at 8 p.m. (not uncommon in the U.S.) may get more benefit from time-restricted eating than the folks in the study did, who in their pre-study lives ate during a 10.3-hour window.

And then there’s the fact that, although the difference wasn’t huge, the calorie plus time-restricted folks did lose more weight than the calorie-restricted-only group. Plus, insulin resistance, triglyceride levels and high blood pressure were more improved in the double-restricted group.

The real conclusion to be drawn from this study is that combining time and calorie restrictions is safe and effective and it’s a helpful way to achieve a healthy weight and a healthier metabolic profile that’s likely to let you live younger longer.

Regaining your health isn’t just about cutting calories and eating in a narrow timeframe. It’s also about improving the quality of your nutrition. That’s why my book is called “What to Eat When.” It offers a smart way to incorporate tasty nutrition into a weight-loss plan that has you eat fewer calories during fewer hours a day.

Q: Why does my doctor say that exercise will help me avoid diabetes-related heart disease? I thought it just came along with Type 2 diabetes, and there was nothing I could do about it. — Richard F., Santa Fe, New Mexico

A: It’s true that heart disease is the No. 1 complication of diabetes. Excess blood glucose causes bodywide inflammation and damages the circulatory system. That puts you at an increased risk for stroke, heart attack, peripheral artery disease, dementia, aging skin, a lousy sex life and more. Elevated glucose levels also damage the nerves in your heart muscle, making heart failure an increased risk. But you can do a lot to ease or prevent the damage. Exercise, along with smart nutrition (plant-based diet and no red or processed meats, added sugars or highly processed foods), is very effective in reducing not only your risk for heart disease but many other complications.

A new study in the journal of the Federation of American Societies for Experimental Biology reveals that one moderately intense 45-minute exercise session encourages the growth of new, healthy endothelial cells lining the outer wall of blood vessels. That, in turn, allows growth of new healthy blood vessels. These are needed because diabetes not only damages blood vessels, it inhibits the growth of new ones.

How does exercise do that? The simple contraction of muscles from walking or running is enough to send submicroscopic packages of beneficial chemicals and chemical messengers into your bloodstream that are needed by damaged cells in the lining of your blood vessels. Those goodies find the needy spots and take up residence, like in-home building contractors, so your body can repair the damage that would otherwise lead to cardiac problems.

So, what constitutes moderate-intensity exercise? It happens when you raise your heart rate and break a sweat. Walking fast (15-minute mile), water aerobics, biking on mostly flat ground (10-12 mph) or doubles tennis all qualify. Enjoy!

Health pioneer Michael Roizen, M.D., is chief wellness officer emeritus at the Cleveland Clinic and author of four No. 1 New York Times bestsellers. His next book is “The Great Age Reboot: Cracking the Longevity Code for a Younger Tomorrow.” Do you have a topic Dr. Mike should cover in a future column? If so, please email questions@greatagereboot.com.