You should total avoid eating oil during weight loss? Which oil is good for health?
Written by: Ms. Sylvia Lam, Accredited Practicing Dietitian APD, Accredited Dietitian HKDA.
It is not necessary to totally avoid eating oil, salt and sugar during your weight loss. Even oil, salt and sugar are placed on the tip of the Healthy Eating Pyramid, it doesn’t mean they do not have their own nutritional value. Actually oil (also called as fats), salt (also called as sodium) and sugar each has their own bodily functions.
CHOOSE THE RIGHT OIL
In fact, fat is one of the very important macronutrients to our body. Fats provide our body with essential fatty acids, help build cell membrane, produce hormone, keep your body warm, enhance absorption of fat-soluble vitamins, give better mouthful and taste to foods and also increase satiety. Besides, good fats intake can help reduce risk of heart disease. Contrarily, if one consumes too little fat, it might negatively impact our health. According to the American USDA Dietary Guidelines for American 2005, if fat consumption is less than 20% of totally daily energy intake, it might lead to inadequate intake of vitamin E and essential fatty acids; which consequently reduce serum good cholesterol (i.e. high-density lipoprotein HDL) and raise serum triglyceride levels. Very low-fat diet (which only consists of 10 – 19% fat) might lead to deficiency in Vitamin E, B12, D and zinc. Adequate intake of fat in each meal actually can prolong satiety, which in turn can reduce unnecessary snacking between meals.
Hong Kong Centre of Health Protection recommends that daily fat consumption should be about 15% – 30% of total daily energy intake. Fats in our foods can be categorized into good of bad fats including saturated fat, unsaturated fats and trans-fat.
- Saturated fat (SFA) – American Heart Association (AHA) 2013 guidelines recommended that saturated fat should not exceed 5-6% of total daily energy intake.
The physical characteristics of saturated fat is in solid form or appear viscid at room temperature. Since saturated fat is proven to increase serum bad cholesterol (i.e. low-density lipoprotein LDL), it is often called the “bad fat”. Saturated fat mainly comes from fatty meat, chicken skin, lard, chicken fat, butter, cream, ice cream and full fat dairy products. Some vegetable oil including palm oil, coconut oil and hard margarine are also high in saturated fat.
- Unsaturated fat – healthy eating should include good oils which contain unsaturated fat.
The physical characteristics of unsaturated fat is in liquid form and viscous. Unsaturated fat mainly comes from plant sources. As unsaturated fat helps reduce serum bad cholesterol and triglyceride, it is often called the “good fat”. It can be classified into two major types:
- Polyunsaturated fat (PUFA)：safflower oil, sunflower oil, sesame oil, corn oil, flaxseed oil, fish oil, soft margarine, nuts and seeds (e.g. walnut and pine nuts)
- Monounsaturated fat (MUFA): canola oil, olive oil, avocado, nuts and seeds (e.g. macadamia nuts, hazelnuts, almond and cashew)
- Trans fat – World Health Organization and American Heart Association recommend intake should be less than 1% of totally daily energy intake.
Trans fat is also a type of unsaturated fat. When liquid-form oil is converted to solid-form by a food processing method named “hydrogenation”, especially partially hydrogenation, trans fat will be produced. Food manufacturers prefer the use of trans fat due to its long shelf life, tasty and stable palatability. As a whole, trans fat has the most negative impact on heart health as high consumption of trans fat can increase bad cholesterol and reduce good cholesterol in our body, which leads to increased risk of atherosclerosis.
The major source of trans fat include margarine, vegetables shortening, partially hydrogenated vegetables oil and foods that we made with them such as pastries, biscuits, cookies, egg rolls, chocolate bars, French fries, chips and also Chinese pastries and dim sum.
Overall, it is recommended to consume less food that are high in saturated fat such as fatty meat, chicken skin, chicken wings, deep fried foods, full fat dairy products, butter, lard, instant noodle, biscuits and high saturated fat vegetables oil including palm oil and coconut oil. One should also reduce intake of high trans-fat food such as Hong Kong style buns, cookies, pastries and Chinese dim sum. Contrarily, one should consume more unsaturated fat as major source of fats from nuts and seeds, avocado, fatty fish, soy bean products such as tofu and bean curd sheet. Good fats can also come from healthy cooking oil such as olive oil, canola oil, corn oil, safflower oil, rice bran oil, flaxseed oil and nut oil.
Based on the Hong Kong Healthy Eating Pyramid, one should consume about 4 to teaspoons of healthy cooking oil per day, and each meal should not exceed 2 teaspoons to be adequate.
How dietary fat impacts heart health:
- The direction of the arrow represents the effect on the rise or fall of cholesterol in the blood. The more arrows, the greater the impact.
- The color of the arrow represents good or bad health. Red represents there is a negative impact on health, while green represents it is beneficial for heath.