No nutrition topic has been as controversial or as hotly debated as the one on fat and whether we should be consuming more or less of this nutrient. For many years we have been told to consume less fat in order to lose/maintain weight as well as to prevent chronic diseases, such as cardiovascular disease (CVD). But a few years ago spanners were thrown in the works, where some research indicated that we should be consuming more fat, even saturated fat which we thought was clearly linked to heart disease, and less carbohydrates. This confused you right? It confused a lot of us, even as professionals in the field of nutrition. So now, a few years on, what is the conclusion on the matter? let’s look at what the research says and what guidelines are now being implemented in order to guide you to making your own decisions.
WHAT IS THE SITUATION IN AMERICA?
The US Department of Agriculture as well as the Department of Health and Human Services release the Dietary Guidelines for Americans every 5 years. This is done so that the guidelines are always based on the latest research. The Dietary Guidelines Advisory Committee (DGAC) is essential to this process, as they systematically review what the literature states and provide a report with evidence-based recommendations to the above-mentioned organisations. They then review these recommendations, as well as comments from other parties, such as academics, and finalise the Dietary Guidelines.
So what do the new Dietary Guidelines for Americans state about fat, having taken the above into consideration?
- It is important to include oils as part of a healthy eating pattern, as they are a major source of essential fatty acids (e.g. omega-3) and Vitamin E.
- It is recommended to consume 27g (about 5 tsps) per day as part of a 2000 kcal diet (about average for an adult).
- Although oils are part of healthy eating patterns, they are still a concentrated source of energy and thus the amount consumed should still be within 20 – 35% of total energy (AMDR for fat for adults), without exceeding the total energy required for the day.
- Instead of being added to the diet, oils should replace solid fats.
- Saturated fat should contribute < 10% to the total energy consumed for the day, and should rather be replaced with unsaturated fats while keeping within the AMDR for age.
- Strong evidence indicates that replacing saturated fats with unsaturated fats reduces total blood cholesterol and LDL-cholesterol, and is also associated with a decreased risk of heart disease and death related to heart disease.
- Limit trans-fat intake to as low as possible by limiting foods, such as partially hydrogenated oils in margarines, which contain synthetic sources of trans-fat. This is due to the fact that a number of studies have observed an association between increased risk of CVD with increased intake of trans-fat.
- Aim to eat as little dietary cholesterol as possible, while consuming a healthy eating pattern. In general, foods such as fatty meats and high-fat dairy products that are higher in cholesterol are also higher in saturated fat. Shellfish and eggs can be consumed together with a variety of different choices within the protein food group recommendations.
WHAT IS THE SITUATION IN SOUTH AFRICA?
The debate about fat intake has been huge in South Africa, with Tim Noakes being an advocate of a high intake, and the Association for Dietetics in South Africa (ADSA) being on the other side of the fence. There has been a mass-movement towards the “Banting diet” which is high in fat (including saturated fat), and low in carbohydrates, in order to lose weight, as well as manage some disease conditions (e.g. insulin resistance). ADSA and the Nutrition Society of South Africa (NSSA) have subsequently released a joint statement on low carbohydrate diets for health and weight loss. They indicate that consuming an extreme low carbohydrate diet for reducing risk of disease is not supported by current available evidence. A low carb diet may help some people to lose weight by reducing their total energy intake and achieving an energy deficit, this dietary pattern may be nutritionally unbalanced and very difficult to sustain over time. In this statement, they also say that fat should be included in a healthy diet, but one should focus on the quality of the fat, i.e. the type of fat.
Just as America has the Dietary Guidelines for Americans, South Africa has the Food Based Dietary Guidelines (FBDG), which aid in advising people on what to eat. The FBDG state: “Use fats sparingly. Choose vegetable oils, rather than hard fats”. Furthermore, a group of South African fatty acid and health scientists have adapted guidelines for fat intake, which are in line with international health bodies and current evidence for the country.
The following represents the key guidelines (complex technical ones not shown here) set for South Africans above the age of 2 years:
- Total fat should provide 20 – 30% of total energy intake. High-fat diets are unhealthy.
- Total energy intake must balance energy expenditure. Most of us need to eat less.
- Saturated fat should provide < 10% of total energy intake, and < 7% of total energy in those at risk of cardiovascular disease. Be careful about animal fats and cholesterol.
- The intake of trans-fat should be less than 1% of total energy. Processed foods and processed fats should be minimised or avoided.
The Bottom Line: fat is not your friend and not your enemy. You need to choose better fats as much as possible (realistic) and you need to eat a balanced diet that includes all food groups (blanket or absolute exclusions are usually dangerous) including moderate amounts of good fat. It’s what your mother told you all along, eh?!
This content was provided by FUTURELIFE®.