Nutritionist Shereen Lehman ranks 7 diet plans


With so much information about which eating plans and diets to follow, it’s hard to pick which is best.

Nutritionist Shereen Lehman has done it for you. 

The co-author of Superfoods for Dummies has ranked seven diets from the Mediterranean to the Alkaline diet.

She rated each diet on a scale of one to five, with the highest scores going to those made up of a healthy balance of food groups, and without heavy restrictions.

Here we take you through the various diets, and show how they ranked from best to worst.

1. MEDITERRANEAN DIET 

The Mediterranean diet follows eating habits of countries bordering the Mediterranean Sea

The diet combines the eating habits of countries that border the Mediterranean Sea – mainly Spain, France, Italy and Greece. It is marketed as an eating pattern rather than a structured diet.

It encourages followers to eat less red meat, sugar and saturated fats and to load up on produce, lean protein, nuts and other healthful foods.

Dairy products such as milk, cheese and yogurt are allowed, but in moderation.

According to Lehman, this is the best of the seven. While it can be expensive to maintain, it is the most balanced diet.

‘The Mediterranean diet includes a lot of delicious food and has good variety. Of course, if you need to lose weight you’ll still need to count calories,’ she writes.

2. 5:2 DIET

The 5:2 diet allows eating whatever you want for five days a week and fasting for the other two

A popular weight loss diet, the 5:2 diet consists of five days of ‘normal’ eating – following a typical 2,000 calorie-a-day diet.

The remaining two days are restricted calorie fasts, with 500 calories allowed for women and 600 for men.

Although fasting can severely impact your energy levels, it can also give your digestive tract a rest, Lehman says.

‘It seems to be effective for weight loss and I like that you can eat what you want on regular days,’ she wrote.

3. JUICE CLEANSE DIET 

The juice cleanse diet consists of drinking only fresh squeezed juices and no solid foods

The juice cleanse diet consists of drinking freshly pressed fruits and vegetables for a couple of days to a couple of weeks.

All solid foods and alcohol are to be avoided.

Lehman says she likes that the diet promotes consumption of fruits and vegetables, but notes that it can be high in sugar if too much fruit is used. 

She writes: ‘A juice cleanse is a good way to jump start a diet, assuming you follow it with a healthy balanced diet.’

4. PALEO DIET 

The Paleo diet promotes eating the way that early, Paleolithic humans would have eaten

The Paleo diet is based mainly on foods presumed to have been available to early, Paleolithic humans. 

The diet encourages eating grass-produced meats, fresh fruits and vegetables, and eggs. It discourages cereal grains, dairy and processed foods. 

While Lehman says the diet includes lots of ‘clean’ foods, it lacks several nutrients including calcium and vitamin D.

‘The Paleo diet isn’t balanced, and excludes a lot of healthy foods,’ she writes.

‘If you really want to follow this diet, choose fish for healthy fats and eat a lot of fruits and vegetables, especially dark green leafy vegetables for calcium.’

5. ALKALINE DIET 

The Alkaline diet  is supposed to keep the body’s pH levels balanced and prevent disease

The Alkaline diet comes from the belief that certain foods can affect the acidity and pH levels of bodily fluids, including the blood and urine, and can therefore be used to treat or prevent diseases.

It is meant to keep the PH levels between 7.35 and 7.45 and supposedly improves memory, boosts energy levels, reduces muscle pain, and prevents headaches and bloating.

The only allowed foods are fresh fruits, vegetables, nuts and legumes.

While the pros include increased food and vegetable consumption, many other whole foods are removed. Lehman did not like the limited number of foods available to eat.

She writes: ‘I like that this diet is high in fruits and vegetables, but it’s out of balance – it can be too low in protein, and grains are out of the question. 

‘Your body regulates pH quite well, so the concept doesn’t make sense to me.’

6. DUKAN DIET 

The Dukan diet consists of four phases with the last phase being a lifelong commitment

The diet was created by French nutritionist Pierre Dukan in the 1970s, and published in a book in 2000, as an effort to combat obesity in France

It consists of four phases for weight loss. It allows 100 foods, and the fourth phase is a life-long commitment.

1. The Attack Phase consists of pure protein and creates a kick-start to the diet. During this phase, you can eat 68 high-protein foods that supposedly produce immediate weight loss.

2. The Cruise Phase adds 32 vegetables and will take you to your ‘true weight’. In total, you can select from 100 natural foods. The average length of this phase is based on a schedule of three days for each pound you want to lose.

3. The Consolidation Phase is when you’re at your most vulnerable, as the body has a tendency to quickly regain weight. This phase prevents the rebound effect by gradually returning previously forbidden foods in limited quantities and allowing for up to two ‘celebration’ meals per week. There are five days per every pound lost in the Cruise Phase.

4. The Stabilization Phase is the lifelong phase. There’s a freedom for healthy eating along with three non-negotiable rules:

  • Three tablespoons of Oat Bran per day
  • Walk 20 minutes daily and choose to take the stairs whenever possible
  • Have a pure protein Thursday, i.e. Attack Phase menu.

Although the diet can lead to quick weight loss, it can increase cholesterol levels and has too many rules, according to Lehman.

‘Too many rules, too many restrictions and it can lead to nutritional deficiencies,’ she writes. 

7. BLOOD TYPE DIET 

The Blood Type diet promotes ‘personalized’ eating habits based on your blood type

Claiming to be the most personalized type of diet, the Blood Type diet recommends different foods for different blood types based on the hypothesis that foods react chemically to different blood types.

Type O: High protein, lean meat, fish, vegetables

Type A: Fruits and vegetables, beans, legumes, whole grains

Type B: Green vegetables, eggs, certain meats, dairy

Type AB: Tofu, seafood, dairy, green vegetables

While all of the diets encourage the consumption of healthy, natural foods with no intake of sugary or fatty foods, there is no scientific backing.

Lehman writes: ‘The Blood Type diet is an interesting hypothesis, but there’s no evidence to show that it works so I won’t be recommending it.’