Are you planning to lose weight and considering which diet to pick? When it comes to weight loss, the massive amount of information available on different diets can be overwhelming. Making it even harder, there is extensive misinformation and weight loss programs with questionable ethics. You may be dazzled by anecdotal success stories and diets that advertise “before” and “after” photos and/or testimonials. Some even promise quick weight loss and advertise fad diets that lack scientific evidence of being effective and safe.
For most people, it is difficult to keep weight off for the long-term after losing weight. You will be successful in achieving long-standing results if you choose diets with greater flexibility and fit your personal preferences. Diets that leave you feeling hungry and deprived can cause you to give up. Before starting a weight loss plan, it is important to have as much information and support as possible.
Let us look at some of the popular diets and drill deeper into the specifics, including whether they are flexible, nutritionally balanced and sustainable in the long run.
Balanced Low-calorie, healthy diets
Examples: Dietary Approaches to Stopping Hypertension (DASH), Mediterranean Diet. These are nutritionally balanced, evidence-based diets with multiple health benefits. They are flexible diets, with no foods off limit.
The Mediterranean Diet is a low calorie, healthy diet compromising of:
- high level of monounsaturated fat relative to saturated fat
- moderate consumption of alcohol, mainly wine
- high consumption of vegetables, fruits, legumes, nuts and grains
- moderate consumption of milk and dairy products, mostly cheese
- relatively low intake of meat products
There are several proven health benefits of the Mediterranean Diet, including reduced risk for heart disease, stroke and Type 2 Diabetes.
Dietary Approach to Stopping Hypertension (DASH) diet is a low calorie, healthy diet comprising of:
- 4-5 servings of fruit everyday
- 4-5 servings of vegetables everyday
- 2-3 servings of low-fat dairy everyday
- Less than 25% dietary intake from fat
Research has shown that combining a calorically restricted DASH diet with approximately 25 minutes of physical activity per day has resulted in an average 5.8 kg weight loss over 26 weeks.
Are these flexible diets?
Yes. No foods are off limit.
Are these nutritionally balanced diets?
Yes
Are these diets sustainable long-term?
Yes. These diets are not short term and emphasize permanent lifestyle changes.
Low-fat diets
Example: Ornish
Low-fat diets help patients reduce adiposity and lose weight. Almost all low-fat diets recommend a reduction in daily intake of fat to less than 30% of energy intake. The disadvantage of low-fat diets is that they may be hard to sustain over time.
You should increase the amount of healthy carbohydrates in your diet (e.g., whole grains, fruit, and vegetables) if you try a low-fat diet.
Are these flexible diets?
No
Are these nutritionally balanced diets?
Yes
Are these diets sustainable long-term?
The possibility is there, but it may be hard to adhere over time.
Low-carbohydrates diets
Examples: Atkins, South Beach, Ketogenic
Low-carbohydrate diets have become popular because they are more effective for short-term weight loss than low-fat diets.
Low-carbohydrate diets limit carbohydrates intake between 60-130 grams of carbohydrates per day, and very low-carbohydrate diets to less than 60 grams of carbohydrates per day. The rationale behind these diets is carbohydrate restriction leads to breakdown of glycogen and fluid loss, rather than fat loss.
Low-carbohydrate diets that place attention on types and quantities of carbohydrates, healthy choices of fat, and protein may reduce the risk of Type 2 Diabetes, Coronary Artery Disease, and some Cancers.
Very low carbohydrate diets may not be safe and have frequent side effects, such as constipation, diarrhea, general weakness, rash, muscle cramps and headache.
Are these flexible diets?
No
Are these nutritionally balanced diets?
Some plans may be nutritionally balanced. Nutritional deficiencies are possible for some restrictive plans.
Are these diets sustainable long-term?
The possibility is there, but it may be hard to adhere over time.
High protein diets
Examples: Dukan, Paleo
These diets are recommended for treating obesity and have at least 20% of daily calories derived from protein. High protein diets are more satiating (leave you feeling full) and stimulate thermogenesis. Thermogenesis is heat produced in response to and following the consumption of the meal that increases the metabolism. There is emphasis on lean meats and dairy.
High protein diets may improve weight maintenance.
Are these flexible diets?
No
Are these nutritionally balanced diets?
Nutritional deficiencies are possible for some restrictive plans.
Are these diets sustainable long-term?
The possibility is there, but it may be hard to adhere over time.
Very low-calorie and starvation diet
Example: Optifast
Very low-calorie diets have energy levels between 200-800 kcal/day, with those below 200 kcal/day labeled as starvation diets. The rationale behind these diets is the lower the calorie intake, the more rapid the weight loss. Energy withdrawn from body fat stores is a function of the energy deficit.
These diets are not for everyone and are used short-term with certain people under medical supervision. They are not recommended for women who are pregnant or breastfeeding, or for children who require nutrients for linear growth.
Side effects of these diets include hair loss, coldness and thinning of skin. There is also an increased risk of gallstones due to increased cholesterol mobilization from fat stores.
Are these flexible diets?
No
Are these nutritionally balanced diets?
No
Are these diets sustainable long-term?
No
Intermittent fasting
Intermittent fasting diets have two strategies: alternate-day fasting and time-restricted feeding. Time-restricted feeding involves eating all food within a specified, limited time period of usually 8 hours (stop eating at a designated time daily and then fast 16 hours until the next day).
Evidence for these diets’ efficacy is mixed. The mechanisms by which intermittent fasting affect health are incompletely understood but may include improved insulin sensitivity and anti-inflammatory effects.
Are these flexible diets?
No
Are these nutritionally balanced diets?
No
Are these diets sustainable long-term?
No
Meal replacements
Examples: Jenny Craig, Medifast, Nutrisystem, SlimFast, HMR
Meal replacements take the place of 1 or 2 meals each day. These diets promote more accurate monitoring of calorie intake. One benefit is simplified meal planning.
Are these flexible diets?
No
Are these nutritionally balanced diets?
Balance is achieved if healthy meal choices are made.
Are these diets sustainable long-term?
There is possibility, but one challenge is the high cost of the products.
Dietary supplements that are not recommended
Dietary supplements are widely used. The ones generally not recommended, have not been studied carefully, and lack proof that they are safe or effective, include:
- Ephedra
- Emagrece Sim (also known Brazilian diet pill)
- Herbathin dietary supplement
- Bitter orange (Citrus aurantium)
- Human chorionic gonadotropin (hCG)
- Chitosan
- Chromium
- Green tea
- Hoodia Gordonii
- Hydroxycitric Acid (found in Garcinia Cambogia, Garcinia Indica, Garcinia Atroviridis)
- Conjugated Linoleic Acid (CLA)
The takeaway message
Healthy weight loss is approximately 1-2 pounds a week. Losing weight too fast may create additional health risks, such as muscle loss, nutritional deficiencies and gallstones.
Choose diets that emphasize:
- reduced refined carbohydrates, processed meats and foods high in sodium and trans-fat
- Moderate intake of unprocessed red meats, poultry, eggs and milk
- high intake of fruits, nuts, fish, vegetables and vegetable oils
- minimally processed whole grains, legumes and yogurt
Work with a health care professional who is experienced in helping people lose weight and making the necessary lifestyle changes to keep the weight off long-term. A sustainable lifestyle solution is key in many cases.
