The good oil on a healthy Christmas

With Christmas looming it is that season where energy consumption tends to exceed energy expenditure with the inevitable weight gain that many people could do without. The big question is whether it is possible to plan ahead in such a way that this year just as much fun will be had without putting on weight. This article will attempt to show how you can advise your patients to have a happy and healthy Christmas break.

The challenge is to cope with the overabundance of high energy dense food that will be available during the holiday celebrations. Of course we could get away with not restricting our eating at all but that would mean a lot of extra energy expenditure that may not be possible or acceptable. So the comprimise may be to restrict energy intake a bit and concurrently moderately increase the amount of physical activity over the Christmas holidays.

Food intake

On the energy-in side of the equation how can we enjoy plentiful good food without overconsuming calories? There are two ways. The conventional way is to keep the diet at about 55% carbohydrate, 15% protein and 30% fat. This is a fairly low fat, high carbohydrate/fibre diet and is recommended by health authorities. Such a diet will contain about 30-40 grams of fat.

But what about those people who have a genetic predisposition to craving higher fat food? There is a way around this dilemma following recent research. Dr Karen Walker from the nutrition and dietetics unit at the Monash Medical Centre presented a paper at the Australasian Society for the Study of Obesity (ASSO) conference in Brisbane in September that showed that a diet relatively high in total fat (40% of energy) could, if most of that fat was monounsaturated (MUFA), be a suitable alternative for treatment for people with type 2 diabetes and obesity. When isocaloric energy restricted (5MJ/day) low fat or high MUFA diets are compared in obese subjects, a similar loss of body weight and body fat have been seen on both diets.

What about ad libitum intake of a high MUFA diet? High MUFA meals can have a low to moderate energy density. An example is the typical Mediterranean diet where energy dense olive oil is combined with low energy density, fibre rich vegetables. Because the high fibre food is filling it is difficult to overconsume. In a randomised crossover designed study in people with type 2 diabetes it was found that a high MUFA diet consumed ad libitum over a 12 week period was not associated with weight gain but induced similar loss of body weight as a low fat, fibre rich high carbohydrate diet.

The other bonus with this type of meal is improved glycaemic control and dyslipidaemia. The low incidence of heart disease in Mediterranean countries is well known. All this for a meal that is generally liked and suitable for the hot climatic conditions of our Christmas.

Physical activity

Research by Associate Professor Bob Ross from the division of endocrinology, Queens University, Ontario (1) could give us some more ideas about health promotion for our overweight patients. The aim of this study was to determine the effects of equivalent diet or exercised induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat, skeletal muscle mass, cardiovascular fitness and insulin sensitvity in obese men. The randomised controlled trial looked at 52 obese men over three months. There were four groups - diet induced weight loss, exercise induced weight loss, exercise without weight loss and a control group.

In the exercise groups, a walk of about one hour was calculated to produce negative energy balance equivalent to those men who restricted their eating by 700cal/day but did not exercise.

Men in both the diet and the exercise weight loss group lost on average 7.5 kgm. Weight did not change in the control group or in the group assigned to exercise without weight loss. Exercise induced weight loss reduces total fat and improves cardiovascular fitness more than diet induced weight loss. Men assigned to exercise without weight loss lost some abdominal fat. Therefore caloric restriction, or about an hour of daily exercise without caloric restriction is an effective strategy for reducing obesity in moderately obese men.

Interestingly it was noted that insulin sensitivity improved by about 60% in the weight loss groups, which is more than the 25% seen with metformin and troglitazone - another reason to encourage weight loss in obese patients.

Alcohol

As regards alcohol, although it is not in itself fattening, when combined with fatty food the fat is preferentially stored rather than consumed for energy. However alcohol is not totally benign when it comes to weight gain. Research from several centres shows that food intake tends to increase by up to 200 kcals when alcohol is drunk with a meal (2). This is particularly so if a meal is preceded by high fat pre-dinner snacks and alcohol (eg. beer and nuts). Low alcohol beer may be no less fattening than standard beer but it doesn’t appear to result in the same increase on later food intake.

So in summary, a healthy Christmas message to our patients could be to significantly increase physical activity, to move towards Mediterranean style food and to moderate alcohol intake.

http://www.medicineau.net.au/clinical/obesity/obesit1273.html