Lose more weight with bigger breakfast?

Interesting summary of a study presented at Endo Society Meeting by Dr. Daniela Jakubowicz. Also info about a book.

Breakfast of Champions--and thin people

Corned beef for breakfast

Macronutrient important in the long run for weight loss?

Sacks FM, Bray GA, Carey VJ, et al. Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates. N Engl J Med. 2009;360(9):859-873. Available at: http://content.nejm.org/cgi/content/abstract/360/9/859

Background

The possible advantage for weight loss of a diet that emphasizes protein, fat, or carbohydrates has not been established, and there are few studies that extend beyond 1 year.

Methods

We randomly assigned 811 overweight adults to one of four diets; the targeted percentages of energy derived from fat, protein, and carbohydrates in the four diets were 20, 15, and 65%; 20, 25, and 55%; 40, 15, and 45%; and 40, 25, and 35%. The diets consisted of similar foods and met guidelines for cardiovascular health. The participants were offered group and individual instructional sessions for 2 years. The primary outcome was the change in body weight after 2 years in two-by-two factorial comparisons of low fat versus high fat and average protein versus high protein and in the comparison of highest and lowest carbohydrate content.

Results

• At 6 months, participants assigned to each diet had lost an average of 6 kg, which represented 7% of their initial weight; they began to regain weight after 12 months.
  
• By 2 years, weight loss remained similar in those who were assigned to a diet with 15% protein and those assigned to a diet with 25% protein (3.0 and 3.6 kg, respectively); in those assigned to a diet with 20% fat and those assigned to a diet with 40% fat (3.3 kg for both groups); and in those assigned to a diet with 65% carbohydrates and those assigned to a diet with 35% carbohydrates (2.9 and 3.4 kg, respectively) (P>0.20 for all comparisons).
• Among the 80% of participants who completed the trial, the average weight loss was 4 kg; 14 to 15% of the participants had a reduction of at least 10% of their initial body weight. Satiety, hunger, satisfaction with the diet, and attendance at group sessions were similar for all diets; attendance was strongly associated with weight loss (0.2 kg per session attended).
  
• The diets improved lipid-related risk factors and fasting insulin levels.

Conclusions

Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.

Dopamine and Obesity

This study illustrates the relationship between the availability of dopamine receptors to obesity.

Bromocriptine improves GH levels in Obesity

J Clin Endocrinol Metab. 2008 Sep;93(9):3455-61

CONTEXT: A profound reduction of spontaneous as well as stimulated GH secretion has been consistently observed in obesity. Dopamine promotes GH release through activation of dopamine D2 receptors (D2Rs). Dopamine D2R availability in the brain is reduced in obese humans in proportion to body adiposity. We hypothesized that impaired dopamine D2R signaling is mechanistically involved in the deficient GH secretion associated with obesity.

OBJECTIVE: To test this hypothesis, we studied the effect of short-term bromocriptine (B) (a D2R agonist) treatment on spontaneous 24-h GH secretion in obese women, while body weight and caloric intake remained constant. DESIGN: This was a prospective, fixed order, cross-over study. SETTING: The study was performed in the Clinical Research Center at Leiden University Medical Center. PARTICIPANTS: There were 18 healthy obese women (body mass index 33.2 +/- 0.6 kg/m2) studied twice in the early follicular phase of their menstrual cycle. INTERVENTION(S): Eight days of treatment with B and placebo (Pl) was performed. MAIN OUTCOME MEASURE(S): Blood was collected during 24 h at 10-min intervals for determination of GH concentrations. GH secretion parameters were calculated using deconvolution analysis.

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The figure really shows what's going on here, so I omitted the rest of the abstract. You can see that giving bromcriptine restored the pulsatile secretion of growth hormone in these obese patients. Basal GH secretion was not enhanced and also IGF-1 levels were not significantly changed.

Interestingly, other studies have been done looking at the effects of bromocriptine on other parameters. Theses studies showed that 24-hour glucose, insulin, and leptin levels were significantly reduced, whereas FFAs were enhanced after bromocriptine treatment.

See also:
J Clin Endocrinol Metab. 2006 Aug;91(8):3236-40.
Am J Physiol Endocrinol Metab. 2006 Nov;291(5):E1038-43.

Effects of 2 types of hypoenergetic diets on hormone levels and gene expression

J Clin Endocrinol Metab. 2008 Nov;93(11):4315-22

CONTEXT: Hypoenergetic diets are used to reduce body fat mass and metabolic risk factors in obese subjects. The molecular changes in adipose tissue associated with weight loss and specifically related to the dietary composition are poorly understood.
OBJECTIVE: We investigated adipose tissue gene expression from human obese women according to energy deficit and the fat and carbohydrate content of the diet.
DESIGN AND SETTING: Obese subjects recruited among eight European clinical centers were followed up 10 wk of either a low-fat (high carbohydrate) or a moderate-fat (low carbohydrate) hypoenergetic diet.
SUBJECTS: Two sets of 47 women in each dietary arm were selected among 648 subjects matched for anthropometric and biological parameters.
MAIN OUTCOME MEASURE: We measured adipose tissue gene expression changes in one set using a candidate gene approach. The other set was used to survey 24,469 transcripts using DNA microarrays. Results were analyzed using dedicated statistical methods. Diet-sensitive regulations were confirmed on the other set of subjects.
RESULTS: The two diets induced similar weight loss and similar changes for most of the biological variables except for components of the blood lipid profile. One thousand genes were regulated by energy restriction. We validated an effect of the fat to carbohydrate ratio for five genes (FABP4, NR3C1, SIRT3, FNTA, and GABARAPL2) with increased expression during the moderate-fat diet. CONCLUSIONS: Energy restriction had a more pronounced impact on variations in human adipose tissue gene expression than macronutrient composition. The macronutrient-sensitive regulation of a subset of genes may influence adipose tissue function and metabolic response.

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This is a nice article if only to review the effects of hypocaloric diets on various hormone levels as well as cholesterol levels. There were two diets (1) a low fat, high carb diet and (2) a moderate fat low carbohydrate diet. Table 2 shows the effects of these diets on a 2o parameters including insulin, leptin, cortisol, glucose and various lipids. Both of these diets had a significant effect on many of these parameters, but the low fat diet (not surprisingly) showed a greater reduction in various lipids.

The portion of the article with regards to genetics gets rather deep and is suggested reading only for the most die-hard seekers of knowledge about obesity.