Is your new diet out to heal you or harm you?

by Caleb Mok, as interviewed by Zara Zhuang
13 Jan 2020

Don't hop on to that new diet just yet – we asked an expert dietician on identifying the good from the bad.

Having practised as a dietitian for about four years, Mr. Caleb Mok has observed people going to great lengths around January and February every year for the sake of their appearance. “With all the festive occasions, people tend to feel pressure to maintain their regular weight while attending all the social activities,” he says.

“I notice people would go on diets, such as low-carb diets, skipping meals or fluid diets like soups or shakes, to achieve the drastic weight loss or to compensate for all the calories consumed with the frequent feasting.”

What are some common pitfalls of adopting new diets? 

Though there may be preliminary evidence of weight loss or health benefits for these diets, a lot of the long-term risks and benefits haven't been established; we usually categorize these diets as fad diets.

A common feature is the omission of certain food groups, such as carbohydrates. Hence, the body will lack nutrients.

Another point is that rather than the benefits of following healthy dietary changes, these diets often overemphasize weight loss, which may put dieters under psychological stress and thus at a higher risk of eating disorders, purging behavior, or binge or stress eating.


How can one distinguish between a healthy diet and a fad diet?

First, if you see a tagline like “lose 10kg in 10 days,” there’s a high chance that this weight-loss program is scientifically unproven, because a program that can promise such fast weight loss will have a very stringent dietary plan, with many restrictions placed on even healthy foods like fruit, legumes and whole grains. Plus, a sustainable rate of weight loss is 500g to 1kg per week, so a program that guarantees very fast weight loss usually isn’t burning fats in the body.

When we cut out carbohydrates, the body depletes its glycogen storage, and from there, besides losing glycogen, the body loses water. Next, if we don’t consume adequate protein, the body will produce energy using muscle.

Fats are burned last. So if you follow a strict diet, you just lose water, which isn't sustainable because after that diet period ends, if you resume your normal diet, your weight will quickly bounce back.

Second, you may see claims like “this diet can help burn belly fats” that specify certain parts of the body. This isn’t scientific, because when we burn fats, genetics determine which area of fat storage is burned first.

Third, you may see claims like “no-sweat diet” or “no-exercise diet.”

This is dangerous, because the energy balance equation involves calorie intake and calorie expenditure; the former depends on consuming foods in different food groups in the correct quantities, and the latter on exercise.

You can even achieve a calorie deficit from calorie restriction, but you need to consider this energy expenditure to maintain a sustainable weight loss. 

Next, a fad diet tends to be for a specific period, perhaps two months or 10 days, and after that is over you resume your normal diet, but to maintain a sustainable weight loss or healthy body weight, it's an ongoing process.

Next is diets that encourage you to omit entire food groups. We know that a lot of carb-loaded foods, such as grains, supply nutrients such as vitamins, minerals, antioxidants, fiber and more.

If you omit such food groups, you deprive your body from these nutrients.

Lastly, some diets recommend certain foods to be consumed every day, such as the cabbage soup diet and the grapefruit diet. These diets stress certain ingredients, whereas we should be eating a wide variety of foods to take in a range of nutrients.

Overemphasizing ingredients, even those with health benefits, can be dangerous and extreme. 


What are the features of a good diet, and is there an ideal diet?

An ideal diet in our context encourages consuming a variety of natural foods instead of processed foods, so more vegetables and fruits, whole grains, and fewer refined carbohydrates. Plant-based ingredients play a role in preventing chronic diseases, and fruit, vegetables, beans and legumes are also high in fiber, which ensures satiety and prevents hunger pangs.

Then there’s controlled carbohydrate intake, which involves taking a moderate amount of carbohydrates and improving the quality of the carb choices, such as eating brown rice instead of white rice. And besides advocating healthy food, an ideal diet appreciates flexibility, so that allows room for some feasting, with “cheat” foods taken in moderation, in substitution and sparingly.

I would say 80 to 90 per cent of your meals should follow a healthy dietary pattern: more fruits and vegetables, lean protein and whole grains; fewer sweetened drinks, and switch over to unsweetened drinks or teas. 


What are some conditions that have become prevalent recently, and what kind of impact have they had?

There have been studies showing that people are feeling more lonely compared to people a decade ago. There has been an early onset of diseases or allergic sensitivities that had not been common before.

Especially in developed countries, there are children exhibiting developmental delay because they are exposed to gadgets very early, resulting in attention deficit difficulties. With advances in medical treatment, life expectancy has grown; we live longer, but whether it’s a quality life, that’s debatable.

So all these things have directed research towards preventive medicine and nutrition, and anti-aging and healthy aging.

At the same time, phenomena such as global warming, pollution, soil overuse and overpopulation have caused crops we eat to contain lower nutrient levels, so supplementation becomes something to consider: How do we supplement our diet to ensure adequate nutrient intake to help **** disease or delay the onset of diseases?

These have impacted us and also the scientific studies realm, and a lot of healthcare resources, be it research or otherwise, have been channeled to primary prevention and early screening. 


Has social media changed how people think about health for the better?

To a certain extent, we are better off, because we’re more exposed to different findings on dietary changes or medical advancement, and social media has improved the public’s awareness of health. But the downside is having to judge whether the information is all true and well-established, so we have to be vigilant in investigating the research quoted, whether there’s a paid collaboration or promotion involved, and whether the features of fad diets are present.

As a dietitian, I stay open-minded with different diets people are proposing nowadays. Years ago, mainstream studies discouraged supplements, so if patients came to me and inquired about supplements, I would cut them off.

But at times it's necessary, so if I'm open-minded, I study more, and from there I validate for myself whether something is good or bad. Many health benefits from diets or foods we have confirmed take years to ascertain through research and studies, and some findings were advocated based on the initial phases of studies, so through consulting experts, you can decide whether it’s worth adopting evidence that has shown early signs of promise.

Take alkaline water for example. I would say its long-term benefits have yet to be established, but if my patients are doing regular screening and **** tests show normal results, they feel good about drinking alkaline water and they want to continue, I would say they can, as long as they understand the possible risks and get themselves monitored. 


What you work on isn’t restricted to diet; there’s also the patient’s lifestyle habits and the environmental and social changes taking place in the background. When everything is interconnected, does that make your work challenging?

It does, so I have to keep up with current trends.

For healthcare professionals — not just dietitians, but also doctors, physiotherapists and so on — we have to be observant of the environment and of the person who comes into our consultation room, from the body language to the condition of the teeth; it’s not just about trends in the field.

From this we are able to put forth highly individualized diets or treatment plans that patients can adhere to. Ultimately we want them to have a better quality of life, so this means I have to study a lot on current trends and be open-minded to learn about new diets, so when my patients come in, they can be well-equipped with the information.


Caleb Mok is a representative dietitian with PanAsia Surgery. He trained at the National Heart Institute of Malaysia and Khoo Teck Puat Hospital.