The popular weight loss app Noom brands itself as different from diets, but sets a low calorie goal.
For many users, the suggested calorie goal is too low and can cause side effects, a dietitian says.
Symptoms of undereating can include fatigue, mood swings, brain fog, and disrupted metabolism.
The app previously set a default recommendation of 1,200 calories a day for many users, regardless of body type or weight loss goal. While Noom now suggests a minimum of 1,310 to 1,540, aiming for too low a calorie goal could lead to side effects, according to dietitians.
Undereating can cause mental and physical fatigue as well as risk of serious health conditions over time, registered dietitian Brigitte Zeitlin told Insider.
1,200 calories a day is the recommendation for toddlers, not adults, experts say
Noom users are encouraged to track their food and to stay within a certain calorie range, which was previously set to 1,200 for many users, several of whom spoke to me about the diet. I was assigned a 1,200-calorie goal when I tried the app myself last year.
I'm an active person who lifts weights and does high-intensity exercise six days a week. This was more than 800 calories below the minimum intake recommended for me by the Mayo Clinic and MyFitnessPal.
"That's extremely low. It's not really an adult serving size," Zeitlin said.
1,200 calories is the recommended amount for a toddler, according to a dietitian who reviewed the app for the Seattle Times.
Noom says its much debated 1,200-calorie recommendation is just a suggestion, and that users can adjust their weight loss goals, which will change their calorie limits. Even after I adjusted for the slowest possible weight loss, my daily calorie goal increased to only 1,420. I was told I could "earn" more by meeting my "step goal," the number of steps I took in a day.
Christine Byrne, a dietitian and journalist in North Carolina, said that after tweeting and writing about Noom, she received hundreds of messages from Noom users. Byrne wrote that all but three of the Noom users who contacted her said they'd been assigned a 1,200-calorie goal. Three women said they'd signed up for Noom while they were breastfeeding and got that goal, despite recommendations from the Centers for Disease Control and Prevention that they eat more.
Noom has since updated its approach to calories, according to a representative. The minimum daily calories goals increased by 10%, from 1,200 to 1,310 for women, and from 1,400 to 1,540 for men. The app's default setting is intended for users to lose about two pounds a week, according to a blog post from Noom.
The post cites a guideline of cutting about 3,500 calories to lose one pound of body fat — a metric considered outdated by weight loss experts.
Calorie needs can vary based on activity level and current weight
Losing weight requires a calorie deficit, burning off more calories than you eat.
Some people may need fewer daily calories for weight loss, Zeitlin said, depending on gender, body size, and exercise habits.
Zeitlin said the app doesn't seem to account for individual calorie needs or differences.
"The problem with Noom is that they're not giving you that number based on you," Zeitlin. "The right calorie amount to lose weight is different for everyone. There shouldn't be a standard. It's detrimental, unrealistic and restrictive."
Undereating can cause fatigue, brain fog, hair loss and moodiness
While a small calorie deficit leads to weight loss, cutting calories too severely can have immediate side effects, Zeitlin said, including:
Brain fog and memory lapses
Dry or red skin
Irritability and moodiness
Long-term calorie restriction can disrupt your metabolism and increase the risk of illnesses
Depriving the body of essential nutrients by undereating, particularly if you drop below 1,000 calories a day, can cause more dangerous symptoms over a period of months or years, including:
Stress on the internal organs, including the heart
Increased risk of bone fractures
Weakened immune system
Severe calorie restriction can also be a risk factor for life-threatening problems such as heart failure over time.
"How long before you end up in the hospital depends on how lucky you are," Zeitlin said.
Severe calorie cutting is a risk factor for disordered eating
Another potential risk of very low calorie diets is that they could trigger people with a history of disordered eating, Zeitlin said.
When I signed up for Noom, the process didn't include any questions to screen for this or other factors that might require more specialized attention.
"Apps might be helpful to learn new strategies to stick to your diet, but if you're having more severe issues, you really need specialized treatment," Dr. Robert Hindman, a psychologist with the Beck Institute, told Insider. "I don't know if they have a mechanism for kicking you off and saying you should really see someone for this."
The risk of triggering disordered eating behaviors isn't unique to a 1,200 calorie diet, however.
Zeitlin said any type of restrictive diet can be a trigger, regardless of the specific calorie limit.
A representative for Noom said the app has since added safeguards to prevent users from setting a goal weight below BMI recommendations, or setting calories too low. They also said the app screens out users who are pregnant or have an active eating disorder, although the process is unclear.
Read the original article on Insider