Judgement Day for Weight Loss Diets -

Kaitlin Little

Overwhelmed by the seemingly endless array of weight loss diets? Some promise to curb your appetite, while others claim that cutting carbs is the key. Whether you’ve seen them in best-selling books, social media or blog posts, each diet always claims to be the best. So how on earth do you know what diet to try?

The truth is when it comes to weight loss diets, there’s no one size fits all. If a diet “works” for you, it won’t necessarily work for others. How much you eat —and what you eat—are equally important. But the key to promoting weight loss is tailoring your strategy to suit your lifestyle.

In this article, we take a look at the top 8 trending weight loss diets and review the research behind them.

DASH Diet

The Dietary Approaches to Stop Hypertension (DASH) diet is recommended by several US Health organizations, including the American Heart Association (AHA), as an effective way to manage high blood pressure. The diet emphasizes the consumption of vegetables, fruits, whole grains, skinless poultry and fish, low-fat dairy products, nuts, legumes, and vegetable oils. It limits the intake of saturated and trans fats, sodium (salt), red meat, and processed foods/beverages that contain added sugars.

Does it aid weight loss?

A recent meta-analysis assessed the effectiveness of the DASH diet on body weight and composition in adults across thirteen high-quality human trials. The meta-analysis revealed that adults on the DASH diet lost on average 3 lbs more than controls, and reduced their waist circumference by 0.4 inches more than controls. These effects were greatest in overweight and obese individuals and were more significant when calories were reduced.

The DASH diet is rich in low-calorie foods, such as fruits and vegetables. These foods are also high in fiber, which not only aids healthy digestion but also makes you feel fuller for longer, meaning you can reduce your overall calorie consumption. There are DASH Diet plans available for different daily calorie intakes ranging from 1,200 calories to 3,100 calories. It’s therefore easy to adjust your intake according to your weight loss goals, activity levels, and gender.

Does it enhance health?

Compared to a typical American diet, the DASH diet can significantly reduce systolic and diastolic blood pressure in hypertensive individuals according to a 2015 systematic review published in the British Journal of Nutrition. The systematic review concluded that the DASH Diet reduces cardiovascular risk by 13% over the course of ten years.

Potential pitfalls?

The DASH Diet promotes low-fat and fat-free dairy products, condiments, and salad dressings, which typically contain large amounts of added sugar, and can be higher in calories. Eating these processed low-fat and fat-free foods can inadvertently lead to weight gain and increase insulin resistance.

Several studies found insignificant effects of the DASH Diet on blood pressure, total cholesterol, and fasting glucose levels.

The Zone Diet

Developed by biochemist Dr. Barry Sears more than three decades ago, the Zone Diet is a low glycemic load diet that encourages followers to balance each meal with ⅓ protein, ⅔ carbohydrates and a little bit of healthy fat. The diet was initially designed to reduce diet-induced inflammation, facilitate weight loss and lower risk of chronic diseases. [1]

Daily calories should be obtained from roughly 40% carbohydrates, 30% proteins and 30% fats. Carbohydrates must be restricted to those with a low glycemic index (e.g. carbohydrates that don’t rapidly raise blood sugar levels) such as colorful, non-starchy vegetables, fruits, and legumes. Protein should be obtained from lean beef, poultry, fish, eggs, low-fat dairy, and tofu. Fats should focus on monounsaturated sources, such as almonds, olive oil, and avocados.

Does it aid weight loss?

Studies investigating the potential for weight loss on the Zone diet have shown inconsistent results. For example, the A TO Z Weight Loss Study conducted in 2007 compared weight loss among adult women on the Zone, Atkins, Ornish and LEARN diets, and found that the Zone diet was the least effective after 12 months with an average weight loss of just 3.5 lbs. Conversely, another well-designed clinical trial found that adults on the Zone diet lost more weight in one year compared to those following either the Atkins or Weight Watchers diet (13.2 lbs, 10.9 lbs, and 10.8 lbs respectively). Research has also demonstrated that low-GI diets, like the Zone, reduce appetite and can lower daily calorie consumption when compared to diets with high-GI meals. [2]

Does it enhance health?

It is believed this low-glycemic load diet reduces the rapid release of insulin after a meal, which could otherwise induce hormonal and metabolic changes that increase the risk of chronic diseases, such as heart disease and type 2 diabetes. While some studies support these claims, the underlying science has also been scrutinized. [3]

Nevertheless, research has demonstrated that the Zone diet can reduce cardiovascular risk factors, including reduced LDL cholesterol and triglycerides [4] as well as lower levels of insulin and pro-inflammatory markers, such as C-reactive protein. [5] Another study also found that the Zone Diet improved blood glucose control, insulin resistance and waist circumference in overweight and obese patients with type 2 diabetes. [6]

Potential pitfalls

One of the few downsides to this diet is that it limits the consumption of some healthy carbohydrates that are considered high GI, such as potatoes and bananas.

Paleolithic Diet

The Paleolithic diet (Paleo, Caveman or Stone-Age diet) is designed to mirror what human hunter-gatherers ate thousands of years ago. The theory assumes that our ancestors had much lower rates of chronic disease due to the consumption of unprocessed foods and regular physical activity. While it’s difficult to determine whether the diet actually aligns with what our ancestors ate, this whole-food diet has been linked to an impressive array of health benefits.

The Paleo diet promotes the consumption of whole foods that humans were genetically programmed to eat, such as meat, fish, eggs, vegetables, fruits, nuts and seeds, while discouraging processed foods, such as refined sugar, dairy, and grains. Oils such as olive, coconut, and vegetable oils are included.

Does it aid weight loss?

Various studies have shown that the Paleo Diet is a safe and effective way to lose weight and shave inches off of your waistline. [7] [8] In one study, participants following the Paleo diet lost 10 lbs more in fat mass compared to those following a typical low-fat diet for 6 months. [9] People who follow the Paleo diet are generally more satisfied after a meal and consume significantly fewer calories per day, compared to those on other healthy diets like the Mediterranean. [10]

Does it enhance health?

Research shows the Paleo diet can significantly improve markers for cardiovascular disease within just seven days, including reduced blood pressure, cholesterol, and blood triglycerides. [11] The primal diet ( variant of the Paleo diet) also seems effective at reducing the risk of type 2 diabetes and slowing the progression of the disease by improving insulin sensitivity and glycemic control. [12]

Potential pitfalls?

The Paleo diet generally eliminates caffeine, as well as whole grains, legumes and dairy, which can make it challenging to adhere to for many people.

The Atkins Diet

With more than 45 million copies sold over the last 40 years, the Atkins diet is one of the world’s most popular weight loss diets. The Atkins diet is a high-protein, low-carbohydrate diet designed specifically for weight loss.

The Atkins diet was originally promoted by Dr. Robert Atkins who insisted that you can lose weight by eating as much protein and fat as you like, as long as you restrict your carbohydrate intake.

The Atkins diet is split into four phases, beginning with a two-week induction during which you limit carbohydrates to 20 grams per day. Once your body has adjusted to burning fewer carbohydrates, you can enter phase two, which involves slowly introducing more low-carb, nutrient-dense foods, like vegetables, fruits, and nuts. The next phase, known as pre-maintenance involves fine-tuning your diet by gradually re-introducing more carbohydrates until weight-loss slows down. The last phase, called maintenance, is all about going low-carb for life.

Does it aid weight loss?

Over the last decade, a vast body of evidence has accumulated to support the Atkins diet as a highly effective way to lose weight. Most importantly, studies have consistently found that this low-carb diet leads to significantly greater and faster weight loss than traditional low-fat diets. [13] [14] Furthermore, A TO Z Weight Loss Study conducted in 2007 found that the Atkins diet was also more effective at promoting long-term weight loss in women on the Zone, Ornish, and LEARN diets.

Does it enhance health?

The Atkins diet appears to be more effective at improving heart-health than low-fat diets, with several studies showing it has more favorable effects on blood cholesterol (including increased HDL “good” cholesterol) and triglycerides. [15] It also appears to decrease caloric intake, improve insulin sensitivity, and blood glucose levels in patients with type 2 diabetes. [16]

Potential pitfalls?

Mainstream health authorities have criticized the Atkins Diet for being high in saturated fat and cholesterol content. However, research is now suggesting that saturated fat is not as bad for us as originally thought, and that consuming dietary cholesterol doesn’t significantly raise our blood cholesterol. [17] [18]

Ketogenic Diet

The Ketogenic diet is an ultra-low carb, high-fat diet initially developed for the treatment of severe childhood epilepsy. However, health professionals now recommend the diet as an effective way to manage diabetes and body weight.

The diet generally involves eating approximately 70% fats, 25% protein, and 5% carbohydrates, although there are slight variations in macronutrient breakdown. As a beginner’s rule, it is often suggested that daily carbohydrate intake is limited to 20 grams.

The primary aim is to induce a state of ketosis during which the body burns fat as the primary fuel instead of carbs. When deprived of carbohydrates, our liver converts fatty acids (both dietary and stored fat) into ketones. Ketones are high-energy compounds, which are then used as an alternative fuel for the body and brain.

Does it aid weight loss?

Several studies demonstrate that the ketogenic diet is extremely beneficial for weight loss, especially in overweight and obese individuals, in part due to its high adherence rate. Numerous studies indicate that individuals on the ketogenic diet lose twice as much weight as those following a low-fat calorie restricted diet. [19] [20]

Evidence also suggests the ketogenic diet is highly effective at improving body composition, in particular reducing abdominal fat, which tends to gather around your organs and increases your risk of metabolic disease. [21].

Due to the satiety effect of consuming large amounts of fat, the keto diet tends to reduce your appetite and suppress feelings of hunger, ultimately leading to fewer calories and higher adherence rates. [22] Once followers reach ketosis, the levels of two appetite influencing hormones, leptin and ghrelin, are altered. [23]

Does it enhance health?

Ketogenic diets are shown to improve several risk factors for heart disease, including blood triglycerides, cholesterol, and blood pressure. [24] It is also shown to improve biomarkers for diabetes, including insulin sensitivity and blood glucose levels. [25] The diet is also being used as adjuvant therapy for patients with cancer and Alzheimer’s disease. [26]

Potential pitfalls?

Although this diet is safe for most people, it is not suitable for everyone, including pregnant and breastfeeding mothers. In extremely rare cases, ketogenic diets can cause a life-threatening condition called ketoacidosis, during which ketones build up within the blood causing a dangerous drop in pH.

Also, due to a potentially high intake of saturated and trans fats, the keto diet can lead to an increase in “bad” LDL cholesterol. This is why you need to focus on healthy fats, like avocados, nuts and olive oil. Like most diets, there’s also an adjustment phase, known as the “keto flu” during which the body switches from burning carbs to burning fat as the predominant fuel. Headaches and irritability are common, although keeping well hydrated can help.

Intermittent Fasting

Intermittent fasting is more of an eating pattern, rather than a traditional diet. It involves cycling between periods of fasting, when no food is consumed, and periods of unrestricted eating. The idea is that by the end of the week you consume fewer calories.

There are several different methods, including:

Alternate-day fasting: Switch between days of unrestricted eating and days during which you consume just 25% of daily calorie needs.
Whole-day fasting: 24-hours of fasting once or twice a week on non-consecutive days, such as the 5:2 diet.
Time-restricted fasting: Fast for a specific time frame each day, such as 16 hours followed by an 8 hour eating window.

Does it aid weight loss?

Intermittent fasting has been used for centuries to maintain a healthy weight, and new research has now proven that it is a safe and effective method. [27] In a systematic review of the current scientific literature, intermittent fasting was shown to cause, on average, an impressive 8% reduction in body weight over the course of 12 weeks. [28] Intermittent fasting also appears to preserve up to three times more lean muscle mass when compared to typical calorie restriction.

Does it enhance health?

Intermittent fasting may be beneficial in the prevention of several chronic diseases. The eating pattern is shown to lower inflammation, improve glucose regulation, and increase insulin sensitivity. [29] [30] It may also increase human growth hormone, which can facilitate fat loss. [31] Some studies even suggest intermittent fasting can facilitate DNA repair and protect against Alzheimer’s disease. [32]

Potential pitfalls?

Intermittent fasting is entirely safe for healthy individuals. However, it may not be suitable for those sensitive to blood pressure or blood sugar changes, such as diabetes, pregnant or breastfeeding women and underweight individuals.

Vegan Diet

The vegan diet is a type of vegetarian diet that involves eating only plant-based foods, generally for ethical or environmental reasons. Vegans eliminate meat, poultry, fish, seafood, dairy, eggs and often other animal-derived foods, such as honey from their diet. Ultimately, the vegan diet is very restrictive and revolves around fruits, vegetables, grains, legumes, tofu, tempeh, nuts, and seeds.

Does it aid weight loss?

Although not intended for weight loss, the vegan diet appears to be very effective at reducing fat mass. In a two-year follow-up study, the vegan diet led to three times greater weight loss than a low-fat diet from the National Cholesterol Education Program, despite similar adherence. In another 18-week study, people following a vegan diet lost 9 lbs more than those on a typical American diet. [33]

Does it enhance health?

The vegan diet has been proposed as one of the healthiest ways to eat for longevity. Adopting a vegan diet may significantly reduce your risk of type 2 diabetes by lowering your blood glucose levels and increasing insulin sensitivity. [34] According to a recent meta-analysis, plant-based diets may also reduce your risk of ischemic heart disease and stroke by 25% and reduce your risk of cancer by 8%. [35]

Potential pitfalls?

If you are following a vegan diet, you need to be aware of nutrient deficiencies. Without careful planning, exclusively eating plant foods can lead to deficiencies in iron, vitamin B12, calcium, iodine, and omega-3 fatty acids.

The Mediterranean Diet

The Mediterranean Diet is based on the traditional eating patterns of people that lived around the Mediterranean Sea during the early 20th century. According to several extensive population-based studies, these people were remarkably healthy compared to Americans despite similar access to healthcare. Researchers determined that their healthy diet must explain the population’s low rate of lifestyle diseases and significantly longer life expectancy.

Although variance exists among regions, the Mediterranean diet generally involves eating primarily plant-based foods, such as fruits, vegetables, legumes, whole grains, and nuts along with moderate intakes of fish, poultry and low-fat dairy, and low intakes of red meat, packaged foods, and sweets. Olive oil is used instead of butter, while herbs and spices are used to flavor foods, and yes —the occasional glass of red wine is enjoyed too. Importantly, meals are a social occasion to be eaten with family and friends, and exercise is encouraged daily.

Does it aid weight loss?

Although the Mediterranean diet contains a high percentage of fat, research shows it’s generally very successful for weight loss, even more so than traditional low-fat diets. A 2018 systematic review of the current literature found that patients following the Mediterranean diet for 12 months typically lost twice as much weight compared to those on a low-fat diet (22 to 9 lbs vs. 11 to 6 lbs). However, weight loss was similar to other high-fat diets, such as the Atkins. [36] With plenty of high-fiber low-GI foods that reduce appetite, along with healthy fats that increase fat oxidation, it’s little surprise the Mediterranean diet aids weight loss.

Does it enhance health?

An increasingly large number of medical professionals are advocating for the Mediterranean diet as evidence continues to mount in its favor. Recent studies reveal that this “heart healthy” diet not only reduces your risk of cardiovascular disease but also type 2 diabetes, breast cancer, and Alzheimer’s disease. [37] Furthermore, a ground-breaking study in 2018 involving over 7,000 Spanish participants—many of whom were at high risk for a cardiac event—found that those who adhered to the Mediterranean diet for five years had a 30% lower incidence of stroke and heart attack compared to those on a calorie-controlled low-fat diet. [38] What’s more, even in the absence of weight loss, this age-old way of eating is shown to reduce inflammation, which is an underlying factor in many chronic diseases. [39]

Potential pitfalls?

Unlike many other weight loss diets, the Mediterranean eating plan doesn’t specify the precise number of calories to consume from each food group. Instead, it uses descriptive words (such as “low intake” and “moderate amounts”), which leaves quantity open to interpretation. Other than this, the Mediterranean diet stacks up very well in the world of weight loss.

The Bottom Line

When it comes to the foods you eat— quality and quantity—matters. It’s important to understand that no single diet is better than the other. The best diet for you is one that you can stick to in the long run—provided it’s healthy of course! And, as always, please check with your health care provider before beginning any new diet, especially if you have a chronic health condition.

References

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