When you're looking to shed a few pounds, it's easy to get tempted by the many so-called ‘quick fix’ diets that promise rapid weight loss. However, there is no shortcut to sustainable weight loss. Dietitian Sally Shi-Po Poon reviews five of the most popular diets below.
The ketogenic diet is a low-carbohydrate, high-fat eating plan that has been used to control seizures in some people with epilepsy. The diet excludes carbohydrate foods such as grains, dairy, legumes, most fruits and starchy vegetables.
Supporters claim that a ketogenic diet can help burn fat and lose weight efficiently, but evidence on its long-term effects is currently lacking. It may also be challenging to follow this diet as it can cause side effects such as brain fog, fatigue, irritability, headaches and constipation.
A gluten-free diet eliminates all foods containing gluten. Gluten is found in wheat, barley, rye, malt, and cross-contaminated oats. You may lose weight when cutting out energy-dense gluten products such as cakes, cookies, batter-fried foods and beer.
However, gluten-free does not necessarily mean low-calorie, as some gluten-free products actually contain more sugar and fat than their gluten counterparts.
Intermittent fasting involves short periods of fasting with either no food or very small amounts of food, and periods of unrestricted eating. One of the most popular intermittent fasting regimes is the “5:2 diet” where dieters eat less than 500 to 600 kcal two days a week, and eat normally during the remaining five. People can achieve weight loss if they don’t overeat on “feed” days.
However, fasting can make you feel dizzy, irritable and tired, making it difficult to concentrate at work. A lack of energy also makes it more difficult to be physically active. It is definitely not suitable for people with diabetes, due to the risk of hypoglycemia (low blood sugar level).
A raw vegan diet has been linked with weight loss as well as disease prevention. As far as nutrition goes, it can be healthy if you have a nutritionally balanced vegan diet with necessary supplements like vitamin B12. However, it does not guarantee weight loss as some vegan foods contain a similar amount of calories to non-vegan foods.
While some foods are good to have raw, others are more nutritious when cooked, such as tomatoes and asparagus. Some foods cannot be eaten raw at all, such as potatoes, legumes and lentils, and raw foods are not suitable for children, pregnant women, elderly people and cancer patients with weakened immunity.
A juice cleanse involves consuming only vegetable and fruit juice for a short period of time, typically one to five days. Supporters claim it can help detox our body, boost immunity, and shed some pounds quickly. However, evidence to support the claimed benefits is lacking. Basically, our liver and kidneys can remove waste from our body every day.
It is not recommended to do a juice cleanse too often or for an extended period of time, as some key nutrients are lacking, for examples: protein, iron, omega-3 fatty acids, zinc, and calcium. Potential side effects include fatigue, dizziness, nausea, and headaches. Inadequate protein intake can make you lose muscle mass and affect the metabolic rate. Once you resume normal eating, your weight can rebound easily.