Frequent snacking and juicing flagged as common mistakes that can hinder weight loss

A leading medical weight-loss doctor warned that two widely promoted habits — snacking throughout the day and regular juicing — can undermine efforts to lose weight.

Dr. Sue Decotiis, a New York City–based physician who treats patients for medical weight loss, told The New York Post that constant nibbling is “the biggest mistake” people make when trying to slim down. While some nutrition experts point to research suggesting evenly spaced, smaller meals can aid weight loss, Decotiis said frequent eating places an extra burden on insulin and can prevent the body from burning fat.

"Eating frequently, even if it’s low-calorie, demands more work from insulin, which is distracted by needing to metabolize food instead of burning fat," Decotiis said. She recommends that most patients, including those taking GLP-1 receptor agonists for weight loss, eat two meals a day and limit snacking. Decotiis also advises prioritizing high-protein snacks when they are chosen, noting that protein digests more slowly, helps preserve lean muscle and promotes greater satiety than carbohydrate-rich options.

Public-health researchers and dietitians have offered caveats to the frequent-snacking approach. A 2022 study cited by proponents of grazing suggested that consuming consistent calories at regular intervals may support weight-loss success for some people. Other experts encourage dieters to assess hunger before eating and to avoid eating out of habit or emotional triggers, which can lead to excess caloric intake.

Remote work has been linked to changes in eating and activity that may worsen weight outcomes. A 2023 survey found that working from home was associated with an average increase of about 800 daily calories consumed and roughly 3,500 fewer steps per day, factors that can contribute to gradual weight gain.

Decotiis also singled out juicing as a common dietary misstep. She said juices are "an all-carbohydrate calorie source with minimal protein and fiber," and that regular consumption typically leads to weight gain rather than loss. Prior research has shown that cold-pressed and other fruit juices can contain sugar levels comparable to sugar-sweetened beverages, and the body metabolizes those sugars similarly to added sugars.

Health professionals emphasize that liquid calories from juice often fail to produce the same feeling of fullness as whole foods. Rebecca Ditkoff, a registered dietitian at Midtown Nutrition, noted that a typical 100 percent apple juice can contain nearly 30 grams of sugar and virtually no fiber, whereas a whole apple has roughly half the sugar and about three to four grams of fiber. That fiber slows digestion and contributes to satiety, reducing the likelihood of consuming additional calories.

Sugary beverages, whether labeled "natural" or not, have been associated in studies with a range of health risks beyond weight gain, including tooth decay, type 2 diabetes, nonalcoholic fatty liver disease, cardiovascular disease and increased mortality. Public-health guidance generally urges people to choose whole fruits over fruit juices and to limit intake of sugar-sweetened drinks.

Practitioners who treat patients for weight loss stressed individualized approaches. While Decotiis recommended two meals and minimal snacking for many patients, she and other experts acknowledge that nutritional needs vary by age, medical condition, medication use and personal preference. For those who do include snacks, experts suggest selecting protein-rich options and timing larger, higher-quality intake earlier in the day rather than late at night, when additional calories are likelier to be retained.

The guidance reflects ongoing debate among nutrition researchers about optimal meal frequency and timing. Some controlled trials have found benefits to more frequent, smaller meals for certain individuals, and others have highlighted the metabolic benefits of time-restricted eating or reduced meal frequency. Clinicians typically advise patients to consider both metabolic effects and behavioral sustainability when choosing a pattern of meals and snacks.

For people aiming to lose weight, the practical takeaways from clinicians interviewed include limiting mindless snacking, favoring whole fruits over juices, choosing protein-centered snacks when needed and tailoring meal frequency to personal medical circumstances and treatment plans. Those taking GLP-1 medications or with specific medical conditions are advised to follow individualized medical guidance from their treating clinicians.