December 8, 2024, 2:47 pm | Read time: 11 minutes

The portfolio diet concept was developed to reduce high cholesterol levels and the risk of cardiovascular diseases. Graduate ecotrophologist and FITBOOK author Beke Enderstein explains how the principle of the portfolio diet works and, in addition to numerous advantages, also mentions possible weaknesses. She also provides an overview of the foods that a diet plan should include in order to successfully reduce high cholesterol levels.

What is the Portfolio Diet?

The portfolio diet is a dietary approach designed for individuals with hypercholesterolemia, focusing on a nutrient-dense, whole-food-based eating pattern. The basis of this diet method is a special plant-based diet plan that recommends foods that have been proven to reduce high cholesterol levels – provided that the permitted foods are served as an alternative to unsuitable foods such as ready meals or sausage.

For example, if you replace light wheat toast with wholemeal oat bread and butter with margarine enriched with plant sterols, you have already fulfilled two key diet tips in the portfolio nutrition plan.

Tip: FITBOOK presents further culinary examples of how a diet plan is put together according to the portfolio philosophy under “Which foods are allowed?”.

Who Invented the Diet?

The portfolio diet goes back to the British physician Dr. David J. A. Jenkins, who also developed the nutritional concept of the glycemic index. His aim was to develop a plant-based diet to reduce the risk of cardiovascular disease. Jenkins’ nutritional concept was presented by Harvard University as part of a study back in 2011^.3

What the Portfolio Diet Promises

The portfolio diet aims to lower cholesterol levels – more specifically, harmful LDL cholesterol – in hypercholesterolemia, thereby promoting heart health. According to inventor Jenkins, these health effects should unfold as soon as certain plant-based foods, which are said to have a cholesterol-lowering effect, dominate the diet.

The diet should be particularly effective if foods that do not harmonize with a heart-healthy diet are largely avoided and replaced with the portfolio foods.

An example of this approach would be to replace sugared cereals made from wheat flour with conventional milk for breakfast with a nutrient-rich muesli made from oat flakes with soy milk.

Principle of the Portfolio Diet

The scientifically supported portfolio diet is predicated on the concept of consuming a variety of fundamental ingredients, frequently in combination, which have demonstrated cholesterol-lowering properties. The basis is formed by plant-based ingredients with an extra portion of protein and fiber.

The fundamental principle of the portfolio diet incorporates four essential food groups that should be included in the daily menu.

Main Components of the Portfolio Diet:

• Soy protein
• Plant sterols
• Nuts
• Soluble fiber

While animal fat, ready meals, and high-sugar foods should be the exception, plant-based foods such as wholegrain products, vegetables, and the like are on the green list – and should be served daily. In addition to classic foods such as oatmeal and nuts, other foods such as tofu, tempeh, and diet margarine are part of the portfolio menu.

Sustainability
In addition to nutritional recommendations, ethical and environmental factors are also integrated into the nutritional concept to enable a holistic approach. In other words, the vegan-oriented portfolio diet is about creating a harmonious link between nutrition, health, and the environment so that all three pillars benefit.

A meal plan based on an average person with an energy requirement of 2000 kilocalories per day provides the following composition as a guide.

Portfolio Diet at a Glance

• 1 handful of nuts
• approx. 20 g soluble fiber from oats, berries, barley, psyllium, apples or oranges
• approx. 50 g vegetable protein from soy products (and other pulses)
• approx. 2 g of margarine enriched with plant sterols

The Rules

In contrast to many other diet concepts, there are no strict rules or prohibitions with the portfolio diet. The focus is on the frequent consumption of “cholesterol-lowering foods,” which ideally replace foods that have the opposite effect. Nevertheless, even foods such as butter or sausage, which increase cholesterol levels, are not completely banned – as long as their consumption is significantly reduced in favor of soluble fiber, vegetables, and the like.

The following basic rules show why certain food groups should be included more frequently in the diet plan.

This is what you should follow on the portfolio diet:

1. Eat soluble fiber regularly: Particular attention should be paid to soluble fiber from fruits, vegetables, oats, and the like. This is because these food components bind water and form a gel-like substance in the digestive system. This has the effect of aiding digestion and lowering blood glucose and cholesterol levels^.4 Scientific studies have also shown that soluble fiber can reduce total and LDL cholesterol levels by up to ten percent.
2. Enrich your diet with plant sterols: Studies suggest that consuming 1.5 to three grams of plant sterols per day can reduce LDL cholesterol levels by up to twelve percent^.5
3. Consume soy protein regularly: Not only has the plant-based protein from soybeans been shown to reduce cholesterol levels, but soybeans may also have a positive effect on heart health through other processes, according to research^.6
4. Eat nuts daily: According to an extensive review, eating tree nuts can help lower total cholesterol, LDL cholesterol, and triglycerides^.7

Which Foods Are Allowed?

As already mentioned, basically all foods are allowed, but animal fat, in particular, should be avoided for the sake of heart health. The focus is on fruit, vegetables, and salad in combination with soy protein, whole grains, pulses, nuts, and vegetable fats.

Suitable foods (selection):

• Fruit: berries, apples, oranges, pears, bananas, peaches
• Vegetables: eggplant, broccoli, cucumber, tomato, peppers, spinach, Brussels sprouts, okra, turnips, kale, avocado (botanically a fruit)
• Nuts: Walnuts, almonds, macadamia nuts, pistachios
• Seeds and kernels: Linseed, cashew nuts, chia seeds, sunflower seeds
• Wholegrains and pseudo-grains: amaranth, buckwheat, oat flakes, quinoa, wholegrain rice, wholegrain bread based on oats and barley
• Pulses: kidney beans, red lentils, black beans, chickpeas, lima beans, white beans, yellow peas, brown and black lentils
• Soy protein: tofu, tempeh, soy milk, soy-based veggie patties, soy yogurt, soy-based cold cuts
• Vegetable fats: vegetable oils and margarine enriched with plant sterols

In addition, Dr. David J. A. Jenkins Diet recommends taking certain supplements such as psyllium and plant sterols to optimize the amount of soluble fiber and plant sterols.

Which Foods Are Forbidden?

Although the portfolio diet does not prohibit any foods in principle, it is, of course, still sensible to eat only small amounts of foods that can increase cholesterol levels or the risk of cardiovascular disease or not to eat them at all.

The following overview shows which foods stand in the way of a heart-healthy diet – and should only be included in the diet in small quantities and rarely.

Unsuitable foods:

• Refined carbohydrates: Conventional pasta made from wheat flour, white rice, white bread such as baguette or buttered toast
• Sweets: Cookies, cakes, sweets, baked goods and other sugary foods
• Animal fat: butter, cream, sausage products, high-fat cheese, egg yolk, meat and fish salads in mayonnaise, seafood
• Sugar: household sugar, honey, maple syrup, raw sugar, brown sugar, cane sugar
• Drinks: soft drinks such as lemonade, juice, sweetened tea, energy drinks and other sweetened drinks, alcohol
• Processed foods: potato chips, deep-fried foods such as chips, ready meals

Is the Portfolio Diet Suitable for Everyday Life?

If you put together your own meals, you can easily conjure up delicious, low-cholesterol or cholesterol-reducing dishes. As there are no direct bans, there is nothing to stop you from eating out, going to restaurants, or having a barbecue with friends. After all, the portfolio diet does not rule out minor culinary sins as soon as the focus returns to the four core groups the next day.

If you want to “diet” properly, you can also grill mushroom and vegetable skewers, soy-based or black bean meatballs, and prepare guacamole or a vegan herb butter with an extra portion of fresh herbs, garlic, chili, and turmeric.

Is the Portfolio Diet Balanced?

If the diet is varied and wholesome, the portfolio diet is definitely a balanced diet. Fresh fruit, vegetables, and salad – in combination with whole grain oats, nuts, quinoa, and pulses – result in multi-faceted combinations.

A balanced diet à la Portfolio is rounded off with soy products such as tofu and margarine enriched with plant sterols, high-quality vegetable oils, and an extra portion of fresh herbs, including micronutrients and antioxidants.

A Typical Meal à la Portfolio Diet

Due to the numerous possible combinations, there are almost no restrictions as long as the basic rules are followed.

1. Breakfast: oatmeal muesli with raspberries, psyllium, soy milk, and walnuts; wholemeal oat bread with almond butter or guacamole and an apple; porridge with soy milk and blueberries
2. Lunch: Oat patties with a soy yogurt-based herb dip with a large seasonal salad, lentil curry, baked tofu on spinach with wholegrain rice, Asian vegetable pan, chili sin carne with millet or wholegrain rice, zucchini pasta with bolognese (soy granules)
3. Dinner: Indian dhal, wholemeal oat bread with margarine, smoked tofu, and lamb’s lettuce with a portion of raw vegetables (½ cucumber, two tomatoes), Thai vegetable curry with tofu, black bean or kidney bean meatball with salad, guacamole, and herb quark based on soy yogurt, moussaka with soy granules
4. Snacks: fruit, green smoothie, soy-based protein shake with melting flakes (soluble oat flakes) and berries, soy yogurt with oat flakes, nuts, and grated apple, a handful of nuts, overnight oats with vanilla, soy milk, and strawberries

Who is the Portfolio Diet Suitable for, and Who is it Not Suitable for?

Basically, almost anyone who wants to change their diet to a wholesome, sustainable, and nutrient-rich diet that supports their cardiovascular system can benefit from this type of diet.

Portfolio meets veggie
While it will be easy for people who already eat a vegan or at least plant-based diet to stick to the Portfolio meal plan, it could be a challenge for meat lovers to give up sausage and the like. The same applies to people who appreciate the convenience of ready-made products. Therefore, there must be a willingness to switch to a whole-food diet that is as natural as possible.

Attention allergy sufferers!
The diet is not suitable for people who have an allergy to soy or nuts, as both foods are central components of the diet. On the other hand, people who reject strict dietary rules and want a certain degree of flexibility can benefit from the portfolio diet.

Advantages of the Portfolio Diet

One of the primary advantages of the Portfolio Diet is its foundation in scientific research, with the four cornerstone ingredients having demonstrated efficacy in lowering cholesterol levels. But the nutritional concept for hypercholesterolemia has even more highlights to offer!

The Advantages at a Glance

• Sustainable nutritional concept
• Scientific background
• Easy to implement
• No strict prohibitions
• Lots of fruit and vegetables
• High-fiber whole foods
• Suitable for vegans
• Rich in micronutrients
• Rich in omega-3 fatty acids
• No sugar, as far as possible
• Healthy, nutrient-rich ingredients
• Rich in secondary plant substances (antioxidants)
• Rich in essential amino acids
• No meat, as far as possible
• Satiety thanks to protein and fiber
• Studies prove the cholesterol-lowering effect
• Avoidance of convenience products as far as possible

Disadvantages of the Portfolio Diet

One of the weak points of the diet is that the selection of foods is “only” aimed at reducing cholesterol levels. Nevertheless, the recommended ingredients in the overall package are sensible and provide numerous healthy ingredients.

The Disadvantages at a Glance

• Not suitable for nut allergy sufferers
• Not suitable for soy allergy sufferers
• Recommendations for an overall healthy lifestyle are missing*

*physical activity, relaxation, smoking cessation, etc.

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Nutritional and Physiological Conclusion

The Portfolio Diet is a scientifically sound nutritional concept that is convincing both nutritionally and in terms of sustainability. Although the focus is on reducing cholesterol and animal fat, a multi-faceted diet à la Portfolio is balanced, rich in nutrients, and provides numerous cell-protecting antioxidants. This means that the concept can be classified as healthy overall.

The diet may pose challenges for individuals who dislike or are intolerant to soy; while soybeans are indeed a rich source of essential amino acids, minerals, and cholesterol-lowering components, it would be beneficial to also mention alternatives like pea protein-based meat substitutes that can provide comparable health advantages.

In terms of desirable environmental and animal protection, the portfolio diet is definitely ahead of many other diets despite the use of soy products. Especially when regional ingredients of organic quality, such as oat flakes, walnuts, summer berries, etc., are favored. When buying soy, you should also make sure that it is organically grown in order to avoid genetically modified products and dubious soy plantations.