Can "non-fried" be completely equated with health?

Yu Yongchao

Nowadays, whether in supermarkets or on e-commerce platforms, many pre-packaged foods labeled "non-fried" are more popular with customers than their counterparts in the pre-packaged fried category. Puffed snacks, instant noodles, and freeze-dried fruit and vegetable crisps are prime examples. With increasing public awareness of healthy eating, low-oil and oil-free foods are gaining importance, and many consumers believe they are healthier than fried foods in any way.

Are non-fried foods really as healthy as advertised? Is there really a clear dividing line between them and oil-free foods? Today, we'll mainly take puffed snacks as an example and discuss this topic from a nutritional perspective.

Why are fried foods always so delicious?

The allure of delicious food often stems from its appealing color, aroma, taste, and presentation. Undeniably, fried food holds a significant place in Chinese culinary culture. Frying imparts a unique sensory experience to food, with its most prominent characteristics being crispiness and fragrance.

Currently, among pre-packaged foods sold in supermarkets and online stores, those specifically labeled "non-fried" mainly fall into three categories: puffed foods, instant noodles, and freeze-dried fruit and vegetable crisps. It's important to clarify that we are not discussing home cooking methods with oil, but rather the frying processes used in food factories.

Deep-frying uses oil as a heat transfer medium, which can quickly and evenly conduct heat energy, rapidly raising the surface temperature of food to over 100°C. During this process, the moisture in the food rapidly vaporizes and expands, quickly "expanding" the originally dense starch mass into countless tiny gaps. The starch around these gaps then dehydrates and dries into a hard shell, resulting in a crisp texture and stable solid shape. When the temperature exceeds 120°C, the Maillard reaction occurs on the surface of starchy foods. This means that the reducing sugars and proteins in the food, when heated, produce brownish-black melanoidins, resulting in a pleasant golden-yellow color and a caramelized flavor, similar to the color and aroma of toasted bread. This aroma, combined with the oil's fragrance, creates a unique and complex flavor.

In addition, to combat the "greasy" feeling of fat, vendors often add salt to fried foods to stimulate the taste buds and increase appetite.

It can be said that the characteristics of deep-frying are, on the one hand, "oil," which represents the aroma of fat, which perfectly matches the instinctive human desire for high-calorie foods ingrained in our genes; on the other hand, "frying," which means high temperature, possesses color, aroma, and flavor that cannot be achieved by cooking with water as a medium.

High-temperature frying has 6 major hazards

The pursuit of "non-fried" foods stems from the growing awareness in recent years of the health risks associated with fried foods. Therefore, before discussing "non-fried," let's first understand the six major health hazards of fried foods.

1. During the deep-frying process, which involves high-fat and high-calorie foods, the moisture inside the food evaporates rapidly. The gaps created by this evaporation are then filled by oil, a process commonly known as "oil absorption," causing the total calorie content of the food to rise rapidly. Regular consumption of such foods can easily lead to obesity and increase the risk of various chronic diseases such as diabetes, hypertension, and hyperlipidemia.

2. Production of pro-inflammatory substances: At the high temperatures of frying, glucose and protein undergo non-enzymatic glycation, producing advanced glycation end products (AGEs). These substances, once inside the body, accumulate in various tissues, increasing inflammation and oxidative stress levels. This can not only increase the risk of cardiovascular disease but also accelerate skin aging.

3. Production of carcinogens: Starchy foods produce acrylamide when fried at temperatures exceeding 120°C. In 1994, the International Agency for Research on Cancer classified acrylamide as a Group 2A carcinogen, indicating that it is likely carcinogenic to humans.

4. The production of trans fatty acids: At the high temperatures of frying, the double bonds of unsaturated fatty acids undergo cis-trans isomerism, producing small amounts of trans fatty acids, which then adhere to fried foods. Trans fatty acids can increase low-density lipoprotein cholesterol levels and decrease high-density lipoprotein cholesterol levels, promoting the development of cardiovascular disease.

5. Destruction of nutrients: Heat-sensitive vitamins such as vitamins B1, B2, C, A, K, and carotene are destroyed at high temperatures, especially vitamin B1, which is almost completely destroyed.

6. Excessive sodium intake: As mentioned earlier, in order to balance the "smells good and tastes good" and stimulate appetite, fried foods usually contain a lot of salt, with a salty and savory flavor. However, excessive sodium intake will increase the metabolic burden on the kidneys and is a risk factor for diseases such as hypertension and osteoporosis.

Non-fried and oil-free are not the same concept.

While various foods labeled "non-fried" do indeed have a lower fat content than fried foods, they are often less delicious than fried foods.

At this point, some people may think that it's simply a matter of choosing between deliciousness and health (non-fried), but many non-fried foods are not as healthy as they seem. We will analyze this issue from three aspects.

1. No "frying" doesn't necessarily mean no "oil".

Taking puffed foods as an example, according to the definition in the National Food Safety Standard for Puffed Foods, puffed foods are divided into oil-containing puffed foods and non-oil-containing puffed foods. The former includes not only "frying with edible oil" but also "adding and/or spraying edible oil into the product", while the latter strictly refers to "food products without adding or spraying edible oil" (such as some puffed hollow corn sticks).

Therefore, even if a certain puffed food is not fried, it may still contain added or sprayed edible oils. It's just that the heating method has been changed from frying to hot air drying or baking, which reduces the amount of oil used, but it does not mean that no oil is used.

Taking potato chips as an example, those made directly from potato slices and deep-fried are called "whole-cut potato chips." Due to their inconsistent shape, these chips are packaged in nitrogen-filled soft packaging. Whole-cut potato chips can have an oil content of up to 33%, meaning one-third of them are oil, and naturally, they are the most fragrant and popular. Baked potato chips, marketed as "non-fried," use potato flour instead of potato starch. After being mixed with starch and pressed into chip shapes, they are then baked after adding or spraying oil. These chips have a uniform shape and are usually packaged in cylinders or cardboard boxes. They are not as crispy or fragrant as whole-cut potato chips. Baked potato chips have an oil content of 26%, meaning one-quarter of them are oil. Although this is less than whole-cut potato chips, it still exceeds the 20% oil content standard for high-fat foods and is still considered a high-fat food. Furthermore, puffed foods using pressure differential technology, such as shrimp chips and Doritos, generally also contain added oil, with fat content mostly exceeding 20%.

Are there any non-fried puffed foods that don't use oil? Yes, there are, like traditional homemade popcorn, which only has a crispy texture and the aroma of corn. But the popcorn sold in movie theaters now is different; most of it is made with oil and sugar.

2. It contains more ingredients and food additives.

Compared to fried foods, foods labeled "non-fried" do indeed have a lower total oil content, but their color, aroma, flavor, and appearance may also be compromised. To compensate for this, non-fried foods may contain palm oil, stearic acid, or other saturated fatty acids, or even shortening, which may contain trans fatty acids, to maintain their aroma and crispy texture.

However, both saturated and trans fatty acids are widely recognized as detrimental to cardiovascular health. Some non-fried foods also contain leavening agents, emulsifiers, antioxidants, or flavorings. In short, the ingredient lists of non-fried foods are generally longer than those of fried foods, and from a nutritional perspective, it is recommended to choose foods with shorter ingredient lists.

3. The content of harmful substances may not be low.

The same problem with non-fried foods arises with high temperatures. High temperatures are a double-edged sword; while they can create a golden color and caramelized flavor through the Maillard reaction, they can also lead to the formation of advanced glycation end products and the carcinogen acrylamide.

In October 2020, a comparative test of 15 potato chip brands in Shenzhen found that many brands had acrylamide levels exceeding the benchmark level set by the European Union, and the average acrylamide content of baked ("non-fried") potato chips (3441 μg/kg) was higher than that of fried potato chips (547 μg/kg).

This result may seem surprising, but it's not hard to understand. Since the defining characteristics of puffed snacks like potato chips are their crispness and aroma, if they weren't deep-fried, to achieve a similar texture, non-fried foods might actually require higher temperatures or longer baking times during the baking process, which would increase the production of harmful substances.

As for non-fried instant noodles, the situation is different from puffed foods. The main characteristics of instant noodles are dehydration and drying, and easy storage, rather than crispiness and aroma. Therefore, the temperature of hot air drying is usually not too high, resulting in fewer harmful substances generated than in fried instant noodles. The downside is that the noodle cake is difficult to form a loose and porous structure, and the rehydration time is longer when soaking the noodles, making them less "convenient".

The information on the back of the packaging is more noteworthy.

At this point, some people may be confused about how to choose between fried and non-fried foods. In fact, when purchasing food, people often only pay attention to the label on the front of the packaging, checking whether it is "oil" or "not oily," but they don't realize that the information on the back of the packaging is more worthy of attention.

First, you need to look at the ingredient list. The ingredient list is ordered so that the ingredients with higher content appear at the top. If you find that vegetable oil is among the top three ingredients, then even if it is "non-fried", it will still be high in calories.

Secondly, look at the food's nutrition facts label. Typically, this label includes information on nutrients such as energy, protein, fat, carbohydrates, and sodium. Prioritize energy, fat, and sodium. The second column shows the content of that nutrient per serving, and the third column shows the percentage of the daily requirement provided by that nutrient per serving. When comparing similar products, choose the one with the lower value. It's worth noting that some manufacturers use different serving sizes (30g, 40g, 52g, etc.) to make the calories, fat, and sodium appear lower. In this case, consumers need to perform the necessary conversions, specifically calculating the nutrient content per 100g of food before making a comparison.

Finally, pay attention to regular eating habits and a balanced diet. Objectively speaking, there is no such thing as absolute junk food, only an unbalanced diet. Although both fried and non-fried foods are high in fat, it's perfectly acceptable to occasionally indulge in delicious food. As long as you limit your intake of fried foods to no more than three times a month, and no more than 100g each time, it's within a healthy range. At the same time, keep your main meals light, choosing cooking methods that use less salt and oil, such as steaming, boiling, stewing, and braising. By "saving" your fat "quota," you can achieve both deliciousness and health.