We take a look at five popular weight-loss diets and get expert views on each.
#1 The Keto Diet
The keto diet – not to be confused with the low carb, high-protein Atkin’s Diet – involves significantly cutting carbohydrate intake and substituting it with fat. This reduction puts the body into ketosis, a metabolic state in which stored fat is burned for energy. The dieter is allowed to eat meat, poultry, fish, seafood, eggs, cheese and plain yoghurt, nuts, low-carb vegetables and fats, while items that are off-limits include grains, beans, fruit and alcohol.
What the experts say…
According to gastroenterologist DR ANDREA RAJNAKOVA and nutritional consultant VERONICA CAVALLINI of Andrea’s Digestive, Colon, Liver and Gallbladder Clinic, studies have shown that the keto diet is effective in reducing body weight, controlling type-2 diabetes, lowering cholesterol and lowering blood pressure when compared to low-fat diets.
However, they add that more studies are needed to fully understand the potential adverse effects and health benefits of the diet. “What is well known is that the keto diet can be helpful in treating seizures,” they say, “but, as a general weight loss plan, it’s still controversial.”
Drawbacks may include the dieter experiencing “keto flu”, which is a result of the body adapting to the low carb condition. Symptoms, which can last a week or more, commonly include headache, weakness, irritability, constipation, nausea and vomiting. Other symptoms can include fatigue, irregular menstrual cycles, sleep disturbances, and loss of electrolytes such as sodium and magnesium.
How doable is it?
These side effects make this diet very unsustainable in the long run, explains DR MELVIN LOOK, Director of PanAsia Surgery.
“No restrictions on bacon and fatty beef brisket may seem doable at first, but the severe restrictions on nutrient-rich fruits, vegetables, grains and other healthy foods may have long-term effects such as micronutrient deficiencies. The high fat intake may also be unsafe for your heart,” he says.
In order for your body to successfully release ketones to achieve weight loss, you have to eliminate almost all sugars and carbohydrates in your diet, adds Dr Look. “Typically, less than 50g of carbs is allowed; the rest is mostly replaced by a high-fat and adequate protein diet.”
This rigidity is why the diet has such a quick drop-off and is not easy to manage, explains Dr Rajnakova. “Since the keto diet requires the body to remain in a state of ketosis, there is a very little margin for error. This diet can also lead to yo-yo dieting because people cannot stay on a restrictive diet for a long time.”
CALEB MOK, representative dietician from PanAsia Surgery Group, agrees that omitting all carbohydrate containing foods can lead to intense cravings and lower compliance. And, in order to achieve real ketosis, he says portion sizes of different food groups and the ratio of calories contributed by each macronutrient need to be precise. Without this technical knowledge, the diet can be very hard to follow.
If you’re still keen to try it, Caleb recommends consulting a trained professional who can advise you on the nutrient deficiencies and the necessary supplements. “Multivitamins, bone-building nutrients (calcium, vitamin D, vitamin K and magnesium, for example), fibre and probiotics are among the fundamental supplements you should consider,” he says.
#2 The Paleo Diet
Also known as “the caveman diet” or “the hunter gatherer diet”, the paleo diet emphasises high-protein and low-carb consumption with grass-fed meat, seafood, eggs, vegetables and fruit, and healthy fats from nuts, seeds, avocado and olive oil. Basically, anything our Palaeolithic ancestors had access to thousands of years ago can be consumed; this means no processed foods or ingredients (bye bye bread and cereal!) and no dairy products.
In his book The Paleo Diet, Dr Loren Cordain of Colorado State University explains how research shows that the modern diet, full of refined foods, trans fats and sugar, is at the root of degenerative conditions such as obesity, cancer, diabetes, heart disease, Parkinson’s, Alzheimer’s, depression and infertility.
What the experts say…
“There are good aspects to the Paleo diet, though it can be counterproductive by severely limiting your food choices,” says Dr Look. “The recommended lean meats, fish, fruits, vegetables, nuts and seeds are all healthy and nutritious, but there is little scientific backing for the strict avoidance of farmed products being beneficial for health. Prohibiting whole grains, beans and legumes eliminates good sources of prebiotics, fibre and vitamins, and likewise, dairy, which can provide protein and calcium.”
Dr Rajnakova agrees that the exclusion of certain sources of fibre, vitamins and minerals can be detrimental: “In the short term, people may experience low energy levels and bad breath because the body has to adjust to the new fuel for the energy production; changes in bowel habits can also be observed as a result of the low insoluble fibre intake. In addition, a diet high in animal protein may increase the production of an insulin-like growth factor, which has been linked to cancer and cardiovascular disease.”
How doable is it?
The variety of food allowed is very limited and is not easy to adhere to long-term, says Veronica. “For many people, it’s not easy to stay on track with this diet, especially if they have to eat out or travel.
Though grass-fed meat and free-range poultry are becoming more widely available in big cities like Singapore, they’re not accessible everywhere; this makes the diet difficult to comply with, depending on where you are.
Dr Look adds, “While the diet is good in theory because it eliminates processed foods and refined sugars, a stringent paleo diet may not be easily accessible and will certainly be expensive, as wild game and grass-fed animals are costlier than farmed animals.”
#3 The Mediterranean Diet
Based on the traditional healthy eating habits of people living around the Mediterranean Sea, this diet emphasises heart-healthy and plant-based foods, and limits intake of red meat, butter, processed foods and refined sugars. The diet encourages lean proteins like chicken and fresh oily fish (think tuna and salmon), nuts, olive oil, fresh fruits, vegetables, legumes, whole grains, herbs and spices.
According to Caleb, a perfect example of a Mediterranean Diet meal would be salmon sautéed with colourful vegetables in extra-virgin olive oil, garlic, onion, parsley and rosemary, topped with walnuts, sunflower seeds and pomegranate, and finished with a touch of lemon juice and freshly ground black pepper; served with whole wheat bread.
The anti-oxidant and fibre packed diet even allows for moderate wine consumption; not more than two small glasses and one small glass per day for men and women, respectively, Caleb says.
What the experts say…
“This is one of the most studied dietary patterns and has consistently shown benefits in weight loss, cardiovascular health, nervous system, joints, cognitive health, metabolic syndromes, type 2 diabetes, and prevention of other chronic diseases, including cancers,” says Caleb. According to Dr Look, scientific studies of more than 1.5 million healthy adults have shown this type of diet to be related to a reduced risk of cardiovascular disease, cancer, Parkinson’s and Alzheimer’s diseases.
“This is a heart-healthy diet that promotes longevity; it should be seen as an eating pattern with variety and balance that allows you to prioritise foods to enjoy rather than a fad diet or rigid meal plan.”
How doable is it?
According to Dr Rajnakova and Veronica, this diet is very easy to follow because you can have everything in moderation and choose from a variety of foods. Dr Look agrees: “Overall, it’s a diet that can be delicious and sustainable once you adopt a few healthy habits. Eat an abundance of fruits and vegetables, switch to whole grains and nuts, switch from butter and canola to olive oil, and switch from red meat and processed meats to lean poultry and fish.”
#4 The DASH Diet
The DASH (Dietary Approaches to Stop Hypertension) diet was designed to test the effect of a diet rich in plant-based foods on blood pressure. It’s low in sodium and fat, and high in micronutrients such as potassium, calcium, magnesium and fibre. Emphasis is on eating plenty of fruit and vegetables (five servings a day), whole grains, fat-free or low-fat dairy products, fish, poultry, beans, nuts, seeds and vegetable oils, and foods low in sodium – only two-thirds to one teaspoon of salt is allowed daily. It also limits refined sugar intake.
What the experts say…
“The main benefit of the DASH diet is blood pressure control. By reducing sodium in your diet, your kidneys hold on to less excess fluid in the body, lowering your blood pressure as a result,” says DR CLAUDIA CHEW of Complete Healthcare International. “Doctors usually recommend those who have pre-hypertension or a family history of hypertension to follow the DASH diet.”
Other health benefits are linked to the diet, too. “Since this plan is rich in fruit and vegetables, the high fibre content may help to protect against various types of cancer, ease constipation and contribute to intestinal health,” says Veronica. “
Additionally, extra virgin olive oil, nuts, seeds and oily fish contain good fats that have proven health benefits in reducing inflammation, lowering high blood pressure, and reducing the risk of heart disease and stroke.” And, though the primary aim of the DASH diet is not weight loss, Dr Chew says some body weight will be shed because of an overall healthier dietary intake, especially when combined with regular physical activity.
How doable is it?
“Although any diet can have its share of difficult-to-follow components, the DASH diet is generally easy to follow, as it doesn’t restrict entire food groups. You won’t need to buy special pricey foods and there are no hard-to-follow recipes,” says Dr Chew. However, she says alcohol intake is limited; one drink daily for women and two for men.
Dr Rajnakova agrees that this is a feasible diet. “You can eat almost everything in moderation, choosing among a variety of foods. You’re supposed to reduce your salt intake but it’s very easy when you have a variety of herbs and spices available to make your food tastier.”
Of course, as with any diet, moderation and patience is key, says Dr Chew. “Slow and gradual dietary changes usually encourage longer-term compliance and effectiveness. Getting support from your doctor and a dietician is also useful,” she says.
#5 Intermittent Fasting
In recent years, intermittent fasting has become a very popular approach for weight loss. It switches between periods of fasting (or very low calorie intake) and periods of unrestricted dieting where everything can be eaten.
There are various approaches:
• Alternate-day fasting: This is where you alternate days of no food restrictions with days where only one meal is allowed; that one meal provides around 25 percent of your calorie needs.
• Whole-day fasting: Also known as “5:2 intermittent fasting,” this approach consists of eating normally for five days a week and fasting completely (or taking in about 25 percent of calorie needs) for two days a week.
• Time-restricted feeding: This approach limits food intake to specific time windows, with 12 to 16 hours of fasting; for example, meals are eaten from 8am to 4pm only.
What the experts say…
“The principle behind this diet is that, under conditions of food restriction, there is a modification of the hormonal setting with a reduction of the fat storage that is used as a fuel during the fasting days,” says Dr Rajnakova. “Also, the circadian clock is involved in the regulation of metabolism and many hormones, including the appetite-regulating hormones.”
While studies have shown that the stress of intermittent fasting may cause certain metabolic changes that can help with weight loss, lowering cholesterol and blood pressure, and protect against heart disease, diabetes, cancer and Alzheimer’s disease, other studies have shown it to be no more effective than daily calorie restriction – making this diet a controversial one, according to Dr Rajnakova and Veronica.
“Another concern of this diet, especially if followed by teenagers, is that long periods of food deprivation or full fasting increase the risk of overeating when food is reintroduced. This may foster unhealthy behaviours such as an increased fixation on food, and eating disorders. A study that was following 496 adolescent girls, fasting for a 24-hour period for weight control, strongly predicted binge eating.”
Additionally, people following this diet often fill up in their non-fasting days on unhealthy foods like junk food, fried food and sugary drinks, and this can create stomach pain, heartburn, and other symptoms and health problems, says Dr Rajnakova.
“Sure, studies do suggest it can have beneficial effects on body and health, but there are cons to take into consideration and we don’t have the long-term data to determine whether it could be used as safe and healthy practice.”
How doable is it?
“Some studies find a higher dropout rate among intermittent fasters, which can suggest it might not be a sustainable approach in the long term,” says Veronica. The diet is certainly not doable for people with conditions that require food at regular intervals due to medications, such as those with diabetes, cancer or a compromised immune system, say Dr Rajnakova and Veronica. It also wouldn’t be suitable for adolescents in an active growth stage, people with stomach issues, pregnant or breastfeeding mothers, or those with signs of disordered eating.
Directory
Andrea’s Digestive, Colon, Liver and Gallbladder Clinic
#21-11/12 Royal Square at Novena, 101 Irrawaddy Road
6264 2836 | andrea-digestive-clinic.com
Complete Healthcare International
#10-01 Shaw House, 250 Orchard Road
6776 2288 | chi-health.com.sg
PanAsia Surgery
#10-43/44, Mount Elizabeth Novena Specialist Centre
38 Irrawaddy Road
6570 2608 | panasiasurg.com
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This article first appeared in the September 2019 edition of Expat Living. You can purchase a copy or subscribe so you never miss an issue!
