We all know that drinking water is good for us. If you are feeling tired, have some water. Have a dry skin? Have some water. Have a dry throat? Have some water. It is almost like water is the fix to all our issues. May be it is, but not always. So, are we sometimes drinking more water than necessary? What happens then?

Many say that there is an 8x8 rule one must follow when it comes to drinking water.

What is the 8x8 drinking water rule?

Many believe that in the 8x8 rule, eight 240ml glasses of water per day adds up to almost 2 liters. However, it is not in the guidelines in both the UK and the EU health advisory. None of them recommends this specific amount.

So, where did it origin from?

The origins of this rule seem to come from misinterpreted advice given decades ago. In 1945, a US advisory board suggested adults should consume one milliliter of fluid per calorie of food, totaling about two liters for women and 2.5 liters for men. Importantly, this included all drinks and even water-rich foods like fruits and vegetables.

A later book in 1974 recommended six to eight glasses of water daily but also noted that coffee, tea, and even beer could count towards hydration. Yet, the idea of drinking two liters of plain water daily took hold and has persisted ever since.

How Much Water Do We Really Need?

As per experts, drinking 8 glasses of water a day may be unnecessary and the research estimates that the actual requirement is around 1.5 to 1.8 liters per day. This not only includes water, but all kinds of fluids from all sources that we may consume in a day.

Also, studies show that instead of following a rigid routine, what is best is to focus on factors like temperature, physical activity and health conditions for your water intake. Those in hot and humid climate, high altitudes or pregnant or breastfeeding, and athletes may require more water. Whereas those in cooler areas, with a more sedentary lifestyle won't. However, for the average person, thirst is a more reliable guide than any fixed rule.

ALSO READ: What Happens When You Drink Too Much Water?

Science of Hydration and Dangers Of Over hydration:

Water is necessary to transport nutrients, control temperature, and keep organs functioning. We lose water through sweat, urine, and respiration, so staying hydrated is critical. However, dehydration develops only when the body loses 1-2% of its total water content.

A widespread myth is that feeling thirsty indicates that you are already severely dehydrated. Experts argue that thirst is an excellent evolutionary mechanism that ensures us drink when we need to. The body also produces hormones that aid in water conservation when necessary.

Drinking More Water Than Needed:

While drinking too much water is generally harmless, it can cause hyponatremia, a condition in which salt levels in the blood become dangerously low. This can result in brain enlargement, disorientation, convulsions, and, in extreme cases, death.

There have been reports of athletes overhydrating during endurance races, resulting in significant difficulties. Experts caution that simply following hydration myths might be dangerous, stating that thirst remains the greatest signal of when to drink.

Could there be a diet that allows you to eat more and still helps you lose weight? For the longest doctors and health experts praised the Mediterranean diet. This is because it is heart-friendly, and has a mix of fruits, whole grains, vegetables, and sea food. However, new research suggests that even a simpler diet would work better. As per British scientists, by simply cutting out ultra-processed foods, and sticking to unprocessed whole foods could lead to greater calorie reduction and weight loss.

Eating More, And Still Losing Weight? What Is Working

The key is to reduce the intake of calories, which is possible when you cut your ultra-processed foods. In a study, researchers found that people who followed a completely unprocessed diet consumed around 330 fewer calories per day than those who ate more processed food.

What surprised scientists was that participants actually ate more food by volume. Those on the whole-food diet consumed about 57 percent more food overall, yet still ended up eating fewer calories. The reason lies in the type of foods they chose, such as fruits, vegetables, salads, and lean proteins, which are naturally lower in calorie density.

This means people could eat larger portions, feel full, and still reduce their total energy intake.

Read: Ultra-Processed Foods May Add 330 Extra Calories A Day, Study Finds

Why Are Ultra-Processed Foods Problem?

Ultra-processed foods, often called UPFs, include items like ready meals, packaged snacks, sugary cereals, sweets, and hot dogs. These foods are typically high in calories, sugar, unhealthy fats, and additives, while being low in fiber and nutrients.

Ultra-processed foods, engineered with additives, preservatives, and artificial ingredients, now comprise over half the average American diet, based on data from the U.S. Department of Agriculture. Their ubiquity and intensive marketing have made them seem inevitable, but accumulating evidence indicates that the health toll is much more serious than realized.

Under the NOVA food classification system, UPFs are defined by their intensive industrial processing, which is typically used to produce hyper-palatable and highly profitable foods. Yet, the convenience comes with an increasingly large body of evidence showing that these foods contribute to a variety of chronic diseases, including cardiovascular disease, obesity, diabetes, depression, and various forms of cancer.

Researchers say UPFs may quietly push people towards overeating without realizing it. Even small portions can contain a large number of calories, making weight gain more likely over time.

The study suggests that when people are given the option to eat foods in their natural or minimally processed form, they tend to make smarter choices on their own.

Also Read: Are All Ultra-Processed Foods Bad For You? Experts Say Some Are Better Than Others

How Was The Study Conducted?

The research followed 20 overweight adults, including 10 men and 10 women, with an average age of 31. Participants were divided into two groups.

One group followed a two-week diet based on minimally processed foods such as vegetables, fruits, salads, and lean meats. The other group ate a diet rich in ultra-processed foods like hot dogs and ready meals. After two weeks, the groups switched diets.

Importantly, the meals were matched for nutrients such as fat, protein, carbohydrates, salt, and fiber. Despite this, those eating whole foods consumed fewer calories and lost nearly one kilogram in weight.

Feeling Fuller and Reducing Cravings

Researchers believe fruits and vegetables played a key role. These foods are high in water and fibre, which lowers their energy density. As a result, people can eat more without consuming too many calories.

Experts also point out that natural fiber helps people feel full for longer and supports gut health. Fibre can trigger hormones that regulate appetite, reducing cravings and helping with long-term weight control.

What This Means for Everyday Diets

The findings add to growing evidence linking ultra-processed foods to a range of health problems. Studies have previously associated high UPF intake with dozens of illnesses.

In the UK, ultra-processed foods make up about 57 percent of the average diet, one of the highest levels in Europe. Experts recommend that around 80 percent of daily food intake should come from whole or minimally processed foods.

The message from scientists is simple. You do not need complicated diet rules. Choosing foods closer to their natural form may help you eat better, feel fuller, and lose weight more sustainably.

A small study suggests that people who avoid ultra-processed foods (UPFs) consume around 330 fewer calories each day on average—even while eating more by weight. Researchers say that when food is offered in its natural, unprocessed form, people tend to make “much smarter decisions.”

The study, conducted by the University of Bristol, reanalysed data from a U.S. clinical trial with 20 participants, which had found that eating only UPFs leads to overeating and weight gain. The team discovered that people eating solely whole foods naturally chose fruits and vegetables over higher-calorie items like pasta and creamy dishes.

Also Read: 11 Brain And Nerve Symptoms Neurologists Say Can Become Life-Threatening

Ultra Processed Foods: What Are They?

Ultra-processed foods are ready-to-eat products made in factories using industrial methods. They rely on chemically modified ingredients and additives rather than whole foods, and often contain little to no real nutrition. Instead, they are loaded with sugar, saturated fats, and salt, which can contribute to chronic health problems over time.

Ultra Processed Foods: How Whole Foods Change Eating Habits

According to the study, as per The Independent, people avoiding UPFs ate 57% more food by weight. Jeff Brunstrom, professor of experimental psychology at the University of Bristol, explained: “It’s exciting to see that when people are offered unprocessed options, they instinctively select foods that balance taste, nutrition, and satiety while still reducing overall calorie intake. Our dietary choices aren’t random—when food is in its natural state, people actually make smarter decisions than we expected.”

Ultra Processed Foods: Common Examples

According to NOVA, ultra-processed foods are ready-to-eat or ready-to-heat products made mostly from industrial ingredients and additives, rather than whole foods. Common examples include:

• Chips
• Carbonated drinks
• Instant noodles
• Ice cream
• Chocolate
• Biscuits
• Sauces and instant sauces
• Ready-made meals
• Mass-produced packaged bread
• Sausages and hot dogs
• Burgers
• Chicken and fish nuggets
• Instant soup
• Meal replacement shakes and powders
• Candy
• Pastries
• Fruit yoghurt
• Fruit drinks
• Cake mix
• Margarine
• Sweet or savory packaged snacks
• Energy bars

These foods are often high in sugar, salt, and unhealthy fats, and low in natural nutrients.

Ultra Processed Foods: Vitamin Fortification Can Mislead

The research also highlighted a concern: some UPFs meet micronutrient requirements through fortification. For example, pancakes and French toast sticks contained vitamin A. However, participants consuming only whole foods got their vitamin A from carrots and spinach, which are far lower in calories.

Ultra Processed Foods: The Calorie-Micronutrient Trade-Off

Dr. Annika Flynn, senior research associate at the University of Bristol, said: “This suggests that UPFs can deliver both calories and nutrients in a single product, which may lead to overconsumption. Whole foods, on the other hand, maintain a healthy balance, encouraging people to favour nutrient-dense options like fruits and vegetables instead of high-calorie foods such as pasta and meat.”

Ultra Processed Foods: Why This Matters for Everyday Eating

The findings underline how simple changes—choosing minimally processed, whole foods—can naturally reduce calorie intake without feeling restrictive. By letting people eat more volume while cutting energy intake, whole foods may help manage weight and improve overall nutrition.

Health specialists have cautioned that a widely used dairy milk alternative may come with downsides many people are unaware of, especially when consumed first thing in the morning, according to Mirror. Oat milk, a popular plant-based and dairy-free option, is often praised for its fibre content and for being fortified with calcium and vitamin D, both important for bone health. However, dietitians point out that compared to other plant-based milks such as almond milk, oat milk tends to contain higher amounts of carbohydrates, added sugars and oils.

What Is Oat Milk Made Out Of?

Oat milk is a dairy-free, plant-based drink that is commonly valued for its fibre content and added calcium and vitamin D, which support bone strength. That said, health experts note that it generally contains more carbohydrates, sugars and oils than many other plant milks, including almond milk.

Registered nutritionist Jenna Hope explains that oat milk is usually produced by creating a syrup from oats, which is then mixed with water. She adds that many well-known oat milk brands also include added oils, emulsifiers and stabilisers to improve texture and shelf life.

Why Is Oat Milk Bad For Your Health?

Experts say certain aspects of oat milk may negatively affect health, particularly when consumed on its own. Speaking to Parade, registered dietitian Melissa Rifkin said that while oat milk lattes can fit into a healthy diet, they are not nutritionally complete by themselves. She noted that although oat milk offers some fibre, most oat milk lattes are low in protein and fat, two nutrients that help regulate blood sugar levels and promote fullness.

Sharing a similar view, registered dietitian Nour Zibdeh told The Independent that oat milk’s high carbohydrate content can lead to sharp rises in blood sugar when consumed in the morning. This effect is less pronounced with dairy milk, which naturally contains protein and fat that help balance its sugar content.

Ms Zibdeh also told Parade that oat milk is low in protein and fat, which contributes to greater blood sugar spikes. French biochemist and author Jessie Inchauspé, widely known as the “Glucose Goddess”, has also criticised oat milk. In a 2024 interview with American entrepreneur Marie Forleo, she described oat milk as similar to drinking “starch juice”, explaining that oats are a grain and grains are primarily made up of starch.

Should You Replace Oat Milk With Cow Milk?

Overall, nutrition experts tend to agree that cow’s milk offers greater nutritional value. Regular dairy milk intake has been linked to better metabolic and heart health, and cow’s milk contains higher levels of key micronutrients such as phosphorus, which supports healthy bones and teeth, along with calcium, vitamin D, B vitamins and potassium, compared to oat milk.

That said, cow’s milk is not suitable for everyone. Allergies, taste preferences and vegan diets mean many people rely on plant-based alternatives. If oat milk is your preference, there is no need to panic. Experts stress that moderation is key and that oat milk can still be enjoyed as part of a balanced diet.

Choosing oat milk does not mean it needs to be completely removed from your routine. There are simple ways to enjoy it while being mindful of expert advice. For those who love an oat milk latte, pairing it with protein-rich foods such as eggs or Greek yoghurt can help balance blood sugar levels and make the meal more satisfying.