Recent commentary from British nutritionists Rob Hobson and Dwayne Mellor, as cited by the Daily Mail, highlights concerns about fasting days that involve very low calorie intake, intermittent fasting practices, and mono diets. Their message is cautious: these approaches can trigger a dangerous drop in blood sugar and may leave the body short of essential nutrients. In both clinical settings and everyday dieting, such effects should be taken seriously, especially when pursuing rapid weight loss or simple dietary hacks.
When people adopt intermittent fasting by abstaining from food for 16 hours or more, the risk of hypoglycemia rises. Hypoglycemia means the blood sugar falls below safe levels and can manifest as weakness, extreme fatigue, dizziness, and trouble concentrating. In more severe cases, it can cause fainting or pale skin, and it can impair brain function leading to memory problems and mood changes. The nutrition experts emphasized particular caution for individuals who manage diabetes, as their blood sugar regulation may already be fragile. Even if blood glucose control is fairly stable, fasting patterns can disrupt medications and timing, complicating disease management.
Advice from health professionals extends beyond diabetes. They warn that older adults, pregnant people, and those with a history of low blood sugar should avoid fasting days that skip a main meal. The concern is not only about short term energy but about maintaining steady nutrient intake. Skipping meals can also upset sleep patterns, mood, and daily functioning, and may increase risk for falls in older adults or accidents in those who rely on precise routines for their health.
Another important point is that removing entire foods or relying on single-item diets does not reliably supply all the nutrients the body needs. Mono diets—eating only one food or a single category of foods such as apples, cottage cheese, or porridge—tend to lack essential vitamins, minerals, fiber, and protein. Over time this can damage energy levels, cognitive clarity, and overall wellbeing. The take away is simple: balance and variety aren’t luxuries; they are foundations for healthy weight management and long term health. Diet plans that promote variety help support sustained energy, better mood, and steadier blood sugar levels throughout the day.
In practical terms, health professionals encourage people to approach dieting with a focus on gradual, sustainable changes rather than rapid, restrictive patterns. If someone is considering fasting, it is wise to consult a clinician, especially for those with medical conditions or who are taking medications. Education on recognizing warning signs of hypoglycemia, planning meals around balanced macronutrients, and ensuring adequate hydration are all part of safer dietary choices. Ultimately, the goal is to support both physical health and mental clarity, while avoiding hunger-driven decisions that could backfire in the long run. For individuals seeking guidance, many health systems and dietitians offer personalized plans that align with medical history, lifestyle, and nutritional needs, without sacrificing safety or daily functioning.
Experts underscore that safe eating patterns, regular monitoring of how the body responds to changes, and a commitment to nutrient-dense foods are more reliable than strict fasting rules. They advise a steady approach to weight management, one built on consistent meals, wholesome ingredients, and a mindful view of how food affects energy, mood, and concentration. The underlying message remains clear: health and balance should come first, with any fasting plan treated as a temporary adjustment rather than a permanent lifestyle, particularly for those in high-risk groups.