If you’re in your 20s and 30s, you might be able to get away with not doing the best job at prioritizing your health without feeling the impact of it.
Maybe you used to eat whatever you wanted without giving it much thought, drank more alcoholic beverages than your doctor would approve of and definitely didn’t get the recommended eight hours of sleep a night.
But live with reckless abandon when you’re over 50 and you’ll certainly be feeling it.
Sometimes, though, an attempt to adopt new healthy habits can be taken too far. The wellness world can be extreme: cold plunges, ultramarathons, hyperbaric oxygen chambers. Is going to these great lengths for better health truly beneficial or is it all a bit much?
There’s one wellness habit in particular that doctors see many people try: Intermittent fasting. It’s perhaps not even as extreme as the habits mentioned above, but it’s a practice that can backfire and be detrimental when taken too far. The consequences can be especially harmful for people 50 and older.
We asked doctors to explain what can happen when fasting is taken too far, and how to achieve the same results in a less extreme — and much healthier — way.
When fasting goes too far
Many people who are trying to lose weight turn to fasting or food restriction as a way to reduce calories. But according to doctors we talked to, this can backfire. “Fasting goes too far when it starts harming your day-to-day function or relationship with food,” says Dr. Brian Blank, a family medicine physician with Ember Modern Medicine.
Blank explains that dizziness, fainting, irritability, sleep disruption, obsessional thinking about food, binge-restricted cycles or consistently low energy are red flags that food restriction or fasting is being taken too far.
“While food restriction does work to some extent, especially initially, when trying to lose weight, often in the long term it backfires,” says Dr. Barbara Bawer, a family medicine physician with the Ohio State University Wexner Medical Center.
She emphasizes that the body needs adequate calories and nutrients to function properly. “When you restrict intake of vital nutrients, you risk malnutrition, poor immune response, menstrual cycle abnormalities in women and hormonal imbalance overall,” she adds.
Taking food restriction too far can be especially dangerous for people 50 and older. “For those over 50 years of age, food restriction can be more detrimental because of muscle and bone loss, which places individuals at high risk for falls and fractures,” Bawer says, adding that not getting enough nutrients can also impact immune function, making it harder to fight off infections and other illnesses.
“It can also lead to muscle loss because your body breaks muscle down for energy. It leads to fatigue, irritability, cold intolerance, constipation, anxiety, depression and more,” Bawer says, highlighting more ways that food restriction can be dangerous for people 50 and older.
Blank points out that many other adults take medications that can interact with meal timing, or they may be prone to dizziness or lightheadedness if they go too long without eating. This can make fasting or taking food restrictions too dangerous. Bawer adds that aggressive restriction can make it harder to hit protein targets, and that can accelerate age-related muscle loss, which matters for mobility, independence and fall risk.
Dr. Sarah Towne, a family medicine and primary care physician with PlushCare, warns against fad diets, which can be a form of extreme food restriction. If a diet you’re considering recommends cutting out entire food groups, she says it’s a red flag.
“While you may lose a few pounds in the short term, these diets can be unhealthy and are often very hard to maintain. What matters most is long-term change and risk reduction,” she explains.
What works for weight loss?
When it comes to weight loss and supporting health long term, all three doctors say what matters most is having eating habits in place that ensure your body is getting the nutrients it needs and that you’re able to maintain them long-term.
“Generally, eating fewer calories than you burn will lead to weight loss. Eat in moderation and move more. Any strategy that achieves that is likely to result in weight loss. The key is finding something you can stick with that also does not compromise your overall health,” Towne says.
Blank explains intermittent fasting is a form of food restriction that can work long term for some people. “Intermittent fasting and time-restricted eating can improve some cardiometabolic markers like weight, blood pressure and insulin-related measures in certain people, but the evidence is mixed on whether it beats standard calorie reduction when calories and food quality are similar,” he notes.
In other words, intermittent fasting can be beneficial for some people, but simply cutting back on how many calories you’re eating could achieve the same results.
When done properly (in a way that’s sustainable and isn’t depriving your body of nutrients), Towne says, intermittent fasting can be beneficial for blood sugar control and insulin regulation.
Instead of making an extreme change in how you eat, Bawer recommends making small changes that are sustainable to maintain.
Blank agrees. “First, consistency beats intensity. Second, the scale is not the only outcome that matters, especially after 50. The best plan is the one that improves health markers and keeps you strong, energized and living your life, not the one that requires white-knuckle willpower,” he says.
Besides, food is a major source of social connection and enjoyment. And you certainly don’t want to deprive yourself of that.
