Fat Loss - Nutrition & Physiology Factors FILE - Sydney - Sunday 3 June 2001
Matt O'Neill BSpSc, MSc(Nut&Diet)
Nutritionist and Director, bodyScoop.com
The simple but often incorrect assumption made about individuals with excess body fat is that they are sloths and/or gluttons. In reality, there are many physical and emotional factors at play, all influencing what we eat and our response to food.
Matt's presentation seeks to identify the best dietary advice we can share with our overweight and obese clients.
Dieting doesn't work
Severe dieting creates a large negative energy balance. This can trigger a starvation response with negative physiological consequences. Dulloo and Jacquet (1998) underfed 35 men for 6 months to cause a 25% loss in body weight. Metabolism feel by up to the same amount, 25%.
Dieting also has a negative psychological impact. Results from the Australian Longitudinal Study of Women's Health indicated:
· 5+ diets in the last year ... poorer mental health & more physical illness.
· Those who dieted 5+ times it the last year ... 75% higher likelihood of depression.
· More frequent dieting ... 2.7 times more likely to report current binging & 4.2 times purging behaviors.
· Body dissatisfaction strongly related to dieting frequency.
· Onset of dieting before age 15 associated with many of the above. This data suggests there may be an evolution of disordered eating, starting with normal (or natural eating) and moving on to normal dieting, disordered eating and a fully diagnosed eating disorder.
Is fat counting the answer?
In the early 1990's researchers more strongly affirmed that carbohydrate is not fattening, but dietary fat must be limited to induce body fat losses. The rationale included:
· Fat has the highest energy density
· Fat is subject to passive over-consumption
· Fat may contribute more on a kcal-for-kcal basis than other macronutrients Kristal (1990) identified four methods to reduce fat consumption:
1. Exclusion.
2. Substitution
3. Modification
4. Replacement
An ad-libitum eating pattern became the dietary pattern of choice, but it may not be adequate to produce body fat reduction in all clients.
More protein?
Of the macronutrients, protein is most likely to suppress appetite. The satiety response to dietary protein may also be inversely related to habitual protein intake. This may explain why some people report less hunger than others when they adopt a higher protein diet.
For clients who don't appear to eat much protein (little meat or dairy products), increased consumption of lean sources of protein may assist with appetite management. However, there is little evidence to suggest highprotein, low-carbohydrate diets are of any use for long-term weight management,
Appetite management
In an effort to pin-point the correct proportion of macronutrients for fat loss, many people fail to recognise the importance of appetite regulation. An understanding of personal appetite control is vital for weight management as it represents the interface between dietary prescription and lifestyle demands.
Hunger is the biological drive to eat signalled through the hypothalamus. Appetite is the emotional, or socially and psychologically influenced desire to eat.
Eating more low alycaemic index (GI) foods may curb appetite for longer periods.
Clients may even be able to unlearn cravings by eating the craved food in a satisfied state and not when hungry. Gibson and Desmond (1999) discovered that in a group of chocolate cravers, cravings were reinforced when chocolate was eaten in the hungry state.
Restrained eaters may be more likely to binge when their restrictive eating pattern is disturbed. Parents may influence their children in this way.
Food preferences also need to be identified, as some clients may have a sweet tooth and others a 'fat tooth'.
An eating diary is useful and should provide facilities to record; time, location, company, moods, hunger, food and drink consumed, fullness and satisfaction.
An appreciation of different psychological eating styles - contented, clueless, captured, comfort and kamikaze -can also enhance counselling effectiveness.
Hierarchy for dietary intervention
The priority for dietary intervention below can assist with initial assessment of a client's eating pattern and provide and template progress review.
Decrease Increase Fat Fibre Alcohol Variety Sugar Protein Starches
Conclusion
Dietary intervention for fat loss must be approached on an individual basis, based on careful assessment of eating habits and behaviour. The major aim is to safely reduce energy intake without a concomitant reduction in food volume, nutrient value or enjoyment.