Can someone choose the diet  he/she  wants to use to lose weight with?  That would be good empowerment. Loss of choice often makes comfort eating and reward-eating worse. If the Atkins diet works for some, well, they should have the option of using it to their advantage, at least till any evidence for deleterious effects become available. 1 year studies have failed to confirm lipid disturbances on the diet, but what it does to progression of atherosclerosis at the vascular level is probably another issue. Initial weight loss with fat based diet in a study was higher than the carbohydrate based diet. This effect was not maintained at 1 year and seems to suggest that there is no benefit with either diet.   Weight maintenance is as important as weight loss itself, no doubt, but initial weight loss is hugely motivating, increases patient confidence and facilitates further activities to maintain weight loss.

A low carbohydrate diet seems to have potential  beneficial cardiovascular effects, as cvs risk markers are reduced while on a restricted carbohydrate diet. Nutrition & Metabolism 2006, 3:19

Evidence on carbohydrate diets vs. low fat diets: analysis of 3 studies:
 http://www.jr2.ox.ac.uk/bandolier/band113/b113-4.html

Dietary Facts:

The British diet has changed : The overall proportion of fat in the diet rose from 31 % in 1940s to 43% in 1990. The proportion of carbohydrate has fallen from 53% to 45%

The average adult in western Europe walks about 8000-9000 steps daily. This is in contrast to the Amish people in North America who do not use cars and instead walk 18,425 steps daily with 0% obesity in their men and a mere 9% obesity in the women. Med Sci Sports Exerc. 2004 Jan;36(1):79-85.

1 kg fat = 7500 kcals
A daily excess of 100 kcals (equivalent to a small chocolate bar) leads to an increase of approximately 5 kg of fat over 12 months; or 50 kg over 10 years.
An energy deficient diet of about 600 kcal/day below the predicted metabolic rate achieves weight loss of 0.5- 1 kg/week. Or, An average energy deficit of 500-1000 kcal/day produces a loss of 1-2 pound per week.  Am J Clin Nutr. 1998 Oct;68(4):899-917

Eating 3 meals a day (not omitting breakfast) is more likely to facilitate weight loss.  Obes Res. 2002 Feb;10(2):78-82.     Although no excess calorie intake was self reported in those who did not eat breakfast, it is likely that compensatory intermeal snacking or calorie catch up at successive meals happened in this group. (personal view) Whether increased intermeal interval which increases hunger levels and facilitates excessive compensatory eating at successive meals would also have an effect on increased efficiency of absorption of nutrients is an interesting thought. Fatty acid binding proteins can regulate intestinal uptake of lipids and hence an up- regulation of fatty acid binding proteins (eg: FABP-2)  is conceivable as contributory to excessive absorption when eating fewer meals in the day. Why does man have to eat three meals?  Is it something imposed by society? Glycogen stores in the liver (110 gms in a 70 kg weight man) last only about 10 hours during the post absorptive state at night, and just manages to get one through to breakfast from dinner. Replenishing glycogen stores in the morning would then be crucial with breakfast. Omitting breakfast would put a strain on gluconeogenesis from fatty acids which are released by lipolysis facilitated by glucagon through the night. While this lipolysis would decrease fat stores and can clearly produce weight loss in prolonged starvation, would such mechanisms still operate normally if one were to eat bigger meals later on in the day while omitting breakfast? What if the person did not eat a bigger meal in the following meal as many of our obese patients claim? Would there still be a drive by the body to preferentially replenish the used up fat stores specifically in an over-compensating way instead of storing it as glycogen? Anorexic patients who eat less than three meals a day do not become obese at least partly due to the fact that nutrient input is restricted in the few meals that happen. Is the pathogenesis of weight gain in the obese eating merely two meals  in a day, clearly related to an excessive drive by central neural mechanisms to overeat due to disruption or up-regulation of neuropeptides in the hedonic opioid system in the brain or the reward centres?

VLCD (Very Low Calorie Diet)  is 800 - 1000 kcal per day
LCD    (Low Calorie Diet)  is 1000- 1500 kcal per day

VLCD diets, though producing greater and more rapid weight loss than LCD diets do not seem to be sustainable. JAMA. 1993 Aug 25;270(8):967-74.   In fact, the more rapid weight loss induction seems to be associated with higher risk of gall stones development.  Am J Med. 1995 Feb;98(2):115-7.     Rapid weight loss (>1.5 kg per week) in adults with significant fatty infiltration in the liver, may worsen non-alcoholic steatohepatitis with increasing necroinflammation, portal fibrosis and bile stasis. J Hepatol. 1991 Mar;12(2):224-9.

Thermic effect of food (dietary thermogenesis) is less for fat, and hence the tendency to gain weight more with fat. (greatest with proteins, intermediate with carbohydrates). MCT (medium chain triglycerides) have higher thermic efficiency (higher postprandial thermogenesis) than LCT, and hence might be the better choice as the predominant dietary fat to facilitate weight loss. Read more on Medium Chain Triglycerides

It is important to note that dietary control improves hyperglycaemia but does not reverse the underlying insulin resistance, unless weight loss is also achieved concomitantly. Hence it is important that type 2 diabetics are not left to fend for themselves with dietary therapy alone, but instead are helped with modalities to improve insulin resistance as early as possible. Read more here.

 Dietary choice in diabetics to lose weight may be different from that of the non-diabetic obese population. High Carbohydrate, low fat diets though shown to be almost as effective as High Fat Low carbohydrate diets, N Engl J Med. 2003 May 22;348(21):2082-90   might bring the risk of elevating triglycerides, lowering HDL and worsening glycaemic control.  N Engl J Med. 2003 May 22;348(21):2074-81. ;  Ann Intern Med. 2004 May 18;140(10):778-85.

Increasing bulk in the diet while maintaining low energy density with increased use of fruits and vegetables,  Med Clin North Am. 2000 Mar;84(2):401-18, vi.   meal replacement products  J Am Coll Nutr. 1994 Dec;13(6):608-14.     and smaller portion sizes can all be important facilitators of weight loss.

Chitosan, a deacetylated chitin, is used as a dietary supplement to decrease body weight. Analyses of the few studies available does not show any significant benefits of chitosan for obesity treatment. Cochrane library. 

Pre-diabetic patients (Impaired glucose tolerance and impaired fasting glucose) have been to shown to benefit from weight loss strategies involving predominantly dietary and physical measures, with a reduced progression to overt diabetes. The Cochrane Database of Systematic Reviews 2006 Issue 2

EXERCISE AND WEIGHT LOSS 

Exercise types and the calorie and food equivalents

Driving a Car
80 kcal
slice of bread

Standing relaxed
100 kcal
glass of white wine

Standing doing light work
180 kcal
bag of crisps

Walking 5 km in an hour
260 kcal
1 1/2 pint of beer

walking 7 km in an hour
420 kcal
2 1/2 oz of peanuts

walking 9 km in an hour
600 kcal
two chocolate bars

cross country skiing competitive
1440 kcal
roast dinner with sponge pudding

75 minutes of walking (moderate intensity activity)  or 35 minutes of jogging (vigorous activity) occurring on a daily basis is necessary to maintain long term weight loss.  Am J Clin Nutr. 1997 Sep;66(3):551-6.  Multiple short episodes of exercising is as effective as single sustained bouts! and might improve compliance. JAMA. 1999 Oct 27;282(16):1554-60

Childhood obesity prevention through lifestyle intervention (Planet Health trial): Arch Pediatr Adolesc Med. 1999 Apr;153(4):409-18

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    This page was last updated on: 07/03/2007

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