Now that the Atkins diet has fallen from grace, what type of diet is best for weight loss, and what's the skinny on fat, carbohydrates and protein?

WHICH DIET IS BEST?

The acute fall in demand for Atkins-type low-carb food products, which led to the recent decision of Atkins Nutritionals, the promoter of the Atkins diet, to file for bankruptcy protection, has left many dieters wondering what type of weight loss diet is best. The short answer is: any balanced diet which is calorie-controlled. The US Department of Agriculture offers two dietary paradigms: it's own "Food Guide" - a balanced food plan - and the Dietary Approaches to Stop Hypertension (DASH) eating plan - a diet to reduce raised blood pressure - neither of which merits the description "low-fat" or "low carb". Furthermore, the consensus among most dietitians and nutritionists is that the precise percentage of fat, carbohydrate or protein, matters less than the type of these macronutrients. Put simply, whether you eat 30 or 35 percent of your calories as fat is less important than the type of fat you eat.

FATS TO EAT, FATS TO AVOID

Recommended fats are monounsaturated and polyunsaturated varieties, with most coming from foods like fish, nuts, and vegetable oils. Oily fish, like salmon, mackerel and sardines, are especially nutritious as they contain omega-3 fats which are not manufactured inside the body and must be obtained from food.

The new "bad guys" are saturated fats and trans-fats (AKA hydrogenated fats). It's best to eat less than 10 percent of calories from saturated fats and less than 300 mg/day of cholesterol, while eating as few trans fats as possible. Cheese and beef are the main diet foods which contribute to excessive intakes of saturated fat, while cakes, cookies, crackers, pies, bread, animal products and margarine are largely responsible for the high intake of trans-fats. Eggs, while high in dietary cholesterol, are now regarded as a healthy food.

CURB YOUR REFINED CARBS

The rise in digestive disorders such as diverticulosis, as well as metabolic disorders like insulin resistance and type 2 diabetes, is directly attributable to our modern dietary preference for white flour foods, as well as our overconsumption of foods and drinks with too much added sugar, including: regular sodas, frosted cereals, cakes, and confectionery. Being easily converted to blood-glucose, these refined carbohydrates can lead to excessive levels of blood glucose and insulin - causing appetite swings, cravings and a variety of metabolic problems. And being easily digestible they can also cause calorie overload and weight gain. All this is reflected in the latest Dietary Guidelines which advocate a reduction in refined carbs and a corresponding increase in the consumption of whole grains, like oats, brown rice, basmati rice, whole wheat breads and pasta. Being largely unrefined, whole grains are richer in fiber and nutrients. In addition, they keep us full for longer, which assists appetite and weight control.

BE GUIDED BY THE GLYCEMIC INDEX

The most comprehensive guide to healthy carbs is the Glycemic Index (GI). Originally created to help diabetics control their blood-glucose levels, the GI classifies carb-rich foods into three categories: high-GI, intermediate and low-GI. Put simply, the higher a food's GI value, the faster and greater its impact on blood-glucose, and the more health problems it can cause. Intermediate and low-GI carbs are the basis for the new generation of "GI Diets", which in effect offer all the benefits of traditional low carb diets, without any of the nutritional risks associated with long term carb restriction.

Concerning non-starchy carbohydrates, the message has not changed in years. Eat plenty of fresh fruit and vegetables of all types, including: leafy green vegetables, deep green, yellow, orange or red vegetables; as well as fruits, notably: blackcurrants, cantaloupe, kiwi fruit, mango, all citrus fruits, and strawberries. All these foods contain important micronutrients many of which are beneficial for metabolism and weight management, as well as general health.

DO CARBS CAUSE A SLOWDOWN IN WEIGHT LOSS?

It's not accurate to say that eating carbohydrate has a detrimental effect on weight. True, low carb diets are famous for causing fast initial weight loss, but let me explain how this occurs. When we eat a normal amount of carbohydrate, we burn it straightaway or else store it for future use in the form of glycogen. Point is, each unit of glycogen binds with 3 units of water. When we start a low carb diet, we rapidly use up all our stored glycogen along with the attached water. It is this sudden loss of water which accounts for most of the extra weight lost when starting a low carb diet. Naturally, as we reintroduce carbs into our diet, we rebuild our glycogen reserves and re-absorb water. Thus, it is more accurate to say that restricting carbs causes an unnatural loss of water-weight, rather than saying that eating carbohydrate causes a slowdown in weight reduction.

HOW MUCH PROTEIN DO WE REALLY NEED?

How much protein we need depends on our ideal body weight. This is because protein is not needed by fat cells, only by our lean tissue. According to official US guidelines, the Recommended Daily Allowance (RDA) of protein for adults is 0.8 gram per kilogram (2.2 pounds) of ideal body weight. This RDA is said to meet 97.5% of the population's needs. For example, a woman of 5'4 who is at her ideal weight of 126 pounds needs 45g of protein per day. This amount is easily obtainable as follows:

BREAKFAST (14g protein)
1 cup oatmeal, 1/2 cup skimmed milk, 2 tbsp wheatgerm

LUNCH (18g protein)
Whole wheat pita, 2 oz salmon, sliced tomato and spinach leaves

DINNER (34.5g)
3 oz chicken breast, 1 cup cooked rice, 1 cup mixed vegetables

This daily menu actually includes a massive 66.5g of protein, well over the RDA for a person of her size. Yet it hardly looks like a high protein eating plan, does it? This is because there really is no such thing as a food that is 'just' protein or 'just' carbohydrate - most foods are a combination of protein, carbs and fats. For example, 1 cup of cooked rice has 5g protein even though we think of rice as a 'carb'. The same applies to spaghetti - in most people's mind this is classed as a 'carb' food, yet 1 cup of cooked spaghetti contains 7g protein!

WHICH PROTEIN IS BEST?

Protein from animal foods is marginally better than vegetable protein, although many animal protein sources can be high in unhealthy saturated fat. Ideally, include both vegetarian and low-fat animal protein in your diet.

HOW TO GET 10g OF HEALTHY PROTEIN

Here are some easy ways to meet your daily protein requirements. Provided your weekly diet contains some complete proteins from meat, eggs or milk, vegetable protein is perfectly fine.

1.5oz of white fish
1.7oz of oily fish like salmon
1.1oz of skinless chicken/turkey fillet
1.25oz of pork tenderloin/lean beef
3 egg whites
2.5oz of Brazils
1.25 cups of fat-free milk
1 cup of fat-free yogurt
1/3 cup cottage cheese
1.5oz of hard cheese
1/2 cup of lentils
3/4 cup soybeans
2 cups cooked brown rice
2 cups cooked pasta
2 cups cooked oatmeal
2.5 slices of rye bread
1 tbsp wheatgerm

CONCLUSION

There is no best weight loss diet. Provided you choose foods from all food groups, taking care to select the right type of fats, carbs and protein, the exact percentage of these macronutrients is up to you. As a basic guide, eat 20-35 percent of calories as fat; 45-65 percent of calories as carbohydrate and 10-35 percent of calories in the form of protein.

Linda Smyth B.Sc., RD, aged 51, is a qualified dietitian and nutritional consultant. She is part of the editorial team at http://www.diet-i.com which provides a range of information about diet, nutrition and weight management to more than 5 million visitors per year.

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