Peds21: Fact, Fiction or Truth of Pediatric Obesity

1
Peds-21Fact, Fiction or Truth of Pediatric
Obesity

• The Role of Alternative Therapies/Fad Diets in
  Pediatric Obesity

Nancy F. Krebs, MD, MS, FAAP Co-Chair, AAP Task
Force on Obesity Professor of Pediatrics Universit
y of Colorado
2
Objective

• Examples of 2 popular approaches
• Low carb/high protein diets (Atkins, PSMF)
• Low Glycemic Index (South Beach)
• Background
• Rationale
• Data
• Interpretation

3
Pros Cons of diets for kids

• PROS
• Provide structure that may help child family
  follow
• May result in weight loss initiate positive
  cycle
• Ideally should provide modeling of appropriate
  eating
• CONS
• Fosters the quest for the magic bullet
• Restrictive practices parental control, risk
  of restriction/relapse cycle
• Dieting behavior in adolescents associated w/
  higher weight (Field, J Peds 2003)

4
Target patients Who Why?

• Severely overweight
• BMI gtgt 95th (e.g. gt 175 IBW)
• Co-morbidities
• Family support compliance
• Supervision
• Education
• Monitoring

5
Rationale for Low Carb Diets

• Body is well adapted to burn fat be in ketosis
• Its not normal to have McDonalds and a
  delicatessen around every corner. Its normal to
  starve.

6
Rationale for Low Carb Protein Sparing
Modified Fast

• High protein ( low carb) proposed to minimize
  loss of lean body mass w/ weight loss
• Satiety euphoria
• Better metabolic tolerance in face of insulin
  resistance?
• CHO ?? insulin ? ? fat burning, ?
  hypoglycemia
• Faster weight loss jump start
• Unrestricted in calories restricted in choices

7
Atkins Put to Test

• 63 obese adults randomized to low carb or
  conventional (low fat) diet x 12 mo
• Initial 20 g carb/d ? liberalized
• Met with registered dietitian at 0, 3,6,12 mo
• Weight metabolic outcomes

Foster, NEJM 2003
8
Low Carb vs Conventional Diet - Adults

• RESULTS
• Weight loss
• 3 6 mo Greater in low carb group
• 12 mo not different
• Labs
• Initial ? TC, LDL in conventional
• ?HDL, ? TG in low carb

(30)
(17)
(21)
(33)
(18)
(28)
(24)
(20)
Foster, NEJM 2003
9
Low Carb Diet - Adolescents

• Methods
• Randomized, nonblinded study x 12 wk
• 16 low carb (20 ?40 g/d) 14 low fat (lt 30)
• Overweight (BMI gt 95th ) mean BMI 35
• Outcomes weight, lipids

Sondike et al, J Peds, 2003
10
Low Carb Diet - Adolescents

• Results after 12 wk intervention
• Low Carb lost gt 2x more weight
• - 9.9 vs - 4.1 kg (p lt 0.05)
• Dietary Intake (subgroup)
• LC 1830 kcal LF 1100 (p0.03)
• Lipids
• LC ? TG (p0.07) LF ? LDL (p0.01)

Sondike et al, J Peds, 2003
11
Low Carb Diet Denver Adolescents

• Severely overweight (? 175 IBW)
• Hi protein/low carb vs low fat diet
• Monitor weight, lipids, insulin, body composition
• Intervention x 12 wk f/u at 24 36 wk
• Preliminary results available (n 23)

Collins et al, Pediatr Res, 2004
12
Low Carb Diet Denver Adolescents

• Weight Low Carb lost gt 2x more
• - 9.9 vs - 4.3 kg (p lt 0.01)
• Caloric intake lower for low carb
• LC 1270 vs LF 1440 kcal/d (p lt 0.02)
• Body composition low carb lost more lean body
  mass both lost fat
• Lipids improvements for both groups, no
  difference by diet

13
Denver Low Carb Diet Study Followup 12 wk
after intervention
(11)
(11)
Low Carb - 8.6 ? 8.7 kg from baseline wt
(8)
(12)
14
SummaryHigh Protein/Low Carb Diets

• Greater weight loss, in short term long term?
• Weight loss generally associated w/ lower caloric
  intake
• Highly restrictive diet (compliance?)
• Lipids ? TG ?HDL
• Fat loss ? LBM
• ?? Impact of physical activity??
• Bravata JAMA 03 Bonow NEJM 03 Foster 03,
  Sondike 03, Collins 04

15
South Beach Diet

• Initial brief period of CHO restricting
• Right carbs / right fats
• Avoid refined carbohydrates (?GI)
• Fats olive, canola, soy oils
• Protein ?? diet not designed for children
• Glycemic Index

16
Glycemic Index

• Incremental area under the glucose insulin
  response curve after a standard amount of CHO
  from a test food relative to that of a control
  food (white bread or glucose). (Ludwig, JAMA,
  2002)
• Measures the degree to which eating a particular
  food increases your blood sugar and therefore
  contributes to weight gain. (Agatston,
  S.B. Diet, p 20)
• decreased circulating concentrations of
  fuelsin the post-prandial periodwould be
  expected toincrease hunger and food intake

17
Glycemic Index - Examples

• Food GI Glycemic Load
• Instant rice 91 25
• Baked potato 85 20
• Carrot 71 4
• Banana 53 13
• Peanuts 14 1
• Variables physical form, ripeness of fruit,
  processing, preparation, combinations of foods

18
High GI Foods, Overeating Obesity

• 12 obese teens
• Test meals w/ low, med, high GI
• Plasma levels of fuels and hormones measured
• Food intake x 5 hr after lunch
• Intake after hi-GI meal was 53 gt med-GI meal,
  81gt low-GI
• AUC accounted for 53 variance in food intake

Ludwig DS, Pediatrics 1999
19
Glycemic Index Treatment of Obesity

• 16 adolescents, randomized to
• low GI (45 kcal CHO, 30-35 of fat) or
• conventional diet (55-60 CHO 25-30 fat)
• Intervention x 6 mo, f/u x 6 mo
• Results (low-GI vs conventional)
• ? BMI 1.3 vs 0.7
• Smaller increase in insulin resistance in
  experimental

20
Summary

• Low carbohydrate diets result in greater weight
  loss than low fat diets
• Long term efficacy unknown
• Severely overweight
• Age most experience in adolescents
• Effects on lipids do not appear to be deleterious
• Diets should be undertaken only w/ medical
  supervision monitoring supplements,
  electrolytes/labs, Sx
• S.B.D. Low glycemic index complex, limited
  experience overall diet has some appeal

21
Final Thoughts

• Guidelines for healthy eating, without strict
  dieting, remain the mainstay of treatment
• Dieting behavior is associated w/ greater weight
  gain ? care w/ any diet is warranted
• Research critically important to best target
  dietary ( P.A. behavior) treatments
• Severity - Co-morbidities ( risk groups)
• Age - Long term benefits/effects (/-)
• Implementation (MD ??)
• Format (group/individual)

22
(No Transcript)
23
Arguments against Atkins

• Contrary to decades of research documenting role
  of fat, esp saturated fat, on risk of heart
  disease
• Calories matter fat has 2x the calories of
  carbohydrate fat is fattening
• Deprivation of a single food group ? set-up for
  relapse/rebound compliance hard for some
• Does not teach eating habits to last a lifetime
  obesity is a chronic condition