Content uploaded by Tuncay Delibasi
Author content
All content in this area was uploaded by Tuncay Delibasi on May 05, 2014
Content may be subject to copyright.
SHORT COMMUNICATION
Effects of leptin replacement on macro- and
micronutrient preferences
J Licinio
1,2
, L Ribeiro
1
, JV Busnello
1
, T Delibasi
3
, S Thakur
3
, RM Elashoff
4
, A Sharma
3
, PM Jardack
5
,
AM DePaoli
6
and Ma-Li Wong
1
1
Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine (UM), Miami, FL, USA;
2
Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
3
Department of Psychiatry and Biobehavioral
Sciences, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, USA;
4
Department of Biomathematics, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los
Angeles, CA, USA;
5
UCLA General Clinical Research Center, Los Angeles, CA, USA and
6
Amgen Inc., One Amgen Center
Drive, Thousand Oaks, CA, USA
Background: The mechanisms underlying food choices are complex and involve neuroendocrine and biochemical signaling.
Among neuroendocrine signals, leptin may play a prominent role in food preference.
Objective: This study was designed to obtain an understanding of the effects of leptin replacement on macro- and
micronutrient preferences in leptin-deficient adults.
Design: We studied the effects of leptin replacement on three adults with genetic leptin deficiency during the initial 12 months
of treatment. Dietary intake was measured in our study by weighed food consumption records. Nutrient intake was calculated
using a nutrition analysis software.
Results: After leptin replacement was started, all patients had initially a marked reduction in food intake. The reduction in caloric
intake differentially affected intake of macro- and micronutrients. There was an initial shift toward a higher percentage
consumption of fats and a decrease in the intake of carbohydrates. Significant differences also occurred in 7 distinct types of
macronutrients, 12 vitamins, 11 minerals and 1 amino acid.
Conclusions: We documented several specific leptin-induced changes in macro- and micronutrients intake during the course of
leptin-replacement treatment, the majority of which were not related to the decrease in total caloric consumption.
International Journal of Obesity (2007) 31, 1859–1863; doi:10.1038/sj.ijo.0803703; published online 7 August 2007
Keywords: leptin; macronutrients; micronutrients; vitamins; amino acids; leptin-deficient
Introduction
Replacement therapy with recombinant methionyl human
leptin (r-metHuLeptin) has been described to dramatically
reduce the weight of obese individuals with genetically based
leptin deficiency.
1,2
In an earlier report we showed that food
intake and body weight were significantly reduced after the
initiation of leptin-replacement therapy in three leptin-
deficient adults who had been morbidly obese from two to
four decades before the initiation of treatment.
1
We report in
this article unpublished data on the intake of macro- and
micronutrients of these patients after the start of leptin-
replacement therapy.
Subjects and methods
We studied the effects of leptin replacement on these three
leptin-deficient adults who are members of a highly
consanguineous Turkish pedigree. Two women and one
man have a Mendelian recessive nonconservative missense
leptin gene mutation (Cys-to-Thr in codon 105) resulting in
a leptin molecule that has the same amino acid substitution
as that of the ob/ob mouse. Detailed phenotype and study
protocol were previously described.
1,3
Doses of r-metHuLep-
tin were designed to achieve a normal leptin concentration
based on body fat of 30% in women and 20% in men.
Administration was, therefore, started at low physiological
doses and decreased gradually as patients lost weight to
Received 21 December 2006; revised 5 June 2007; accepted 1 July 2007;
published online 7 August 2007
Correspondence: Dr J Licinio, Department of Psychiatry and Behavioral Sciences
(D-28), University of Miami Miller School of Medicine, 1695 NW 9th Avenue,
Suite 3100; Miami, Florida 33136, USA.
E-mail: licinio@miami.edu
International Journal of Obesity (2007) 31, 1859–1863
&
2007 Nature Publishing Group All rights reserved 0307-0565/07
$
30.00
www.nature.com/ijo
avoid excessive weight loss. Dosage ranged from 0.01 to
0.04 mg/kg. In this report we present the results of the
nutritional intake data collected during the initial 12
months of leptin-replacement treatment.
Patients were flown from Turkey to the United States and
stayed at the UCLA GCRC, facilities for the entire period
described here. The study protocol started with a 2-month
baseline assessment period, designed to deal with confound-
ing factors related to time zone changes and potential
alterations in food choice. After this period, leptin-replace-
ment therapy was started. The last two weeks of the baseline
period is called from now on visit 1 and provides the baseline
data for the period before leptin-replacement initiation. Each
subsequent visit data point is the average of daily assess-
ments of consecutive 2-week periods.
The participants themselves selected foods ad lib from
menus. All food and beverage provided to the study subjects
were then recorded by weight with a precision balance.
Nutrient intake was calculated using a nutrition analysis
software (NutritionistPro, First DataBank Inc., San Bruno,
CA, USA), which bases its analyses on a comprehensive
database of over 18 000 foods and ingredients.
Analysis of variance with repeated measures was per-
formed to test the significant differences over time for each
of the nutritional variables. Pearson’s correlation was
performed to test for the correlation between total caloric
intake and fat percentage and nutrients across the visits. A
significance level of 0.05 was used. Post hoc test was
performed using Tukey’s multiple comparison test. Analyses
were performed using Prism 4.0 (GraphPad Software Inc.,
San Diego, CA, USA), StatView 1.1 (Abacus Concepts Inc.,
Berkeley, CA, USA) and SAS 9.3.1 (SAS Institute Inc., Cary,
NC, USA).
Results
After leptin replacement was started, all patients initially had
a marked reduction in food intake. The mean daily caloric
intake dropped 50%, from 23847946 kcal/day at baseline
(visit 1) to 1179790 kcal at visit 2. After the initiation of
leptin replacement, daily caloric intake decreased, reaching a
nadir at 4–6 months, and thereafter it increased and became
stable.
1
The effects of 18 months leptin replacement on body
weight and body fat percentage, along with the levels of
fasting glucose, insulin, cholesterol, apolipoprotein and
C-peptide were described previously.
1
The reduction in caloric intake affected macro- and
micronutrients intake differently during the first 12 months
of follow-up (Figure 1). Seven macronutrients showed
significant differences between the visits, namely, cholesterol,
polyunsaturated fatty acid (PFA) 18:2 linoleic acid, PFA
18:3 linolenic acid, PFA 20:5 eicosapentanoic acid (EPA), PFA
22:6 docosahexanoic acid (DHA), dietary fiber and sugar. The
macronutrients that did not show differences were saturated
fat, monounsaturated fat, polyunsaturated fat and oleic
(monounsaturated fatty acidFMFA 18:1). The vitamins that
showed differences were vitamin A, C, D and K, b-carotene,
a-tocopherol, riboflavin, pyridoxine, folate, cobalamin,
biotin and pantothenic acid. Vitamin E, thiamin and niacin
did not change across the visits. All of the studied minerals
(except selenium) showed differences between the visits,
namely, sodium, potassium, calcium, iron, phosphorus,
magnesium, zinc, copper, manganese, chromium and
molybdenum. The studied amino acids were tryptophan,
threonine, isoleucine, leucine, lysine, methionine, cystine,
phenylalanine, tyrosine, valine and histidine. Among them
there was only for tyrosine a significant difference between
the visits. The magnitude of these changes and their
temporal patterns are displayed in detail in Table 1. Our
data showed a strong positive correlation between fat
percentage and linoleic acid (PFA 18:2) (r ¼ 0.998,
P ¼ 0.039) in visit 3, and between fat percentage and
cholesterol (r ¼ 1.00, P ¼ 0.0007), monounsaturated fat
(r ¼ 0.999, P ¼ 0.009) and oleic acid (MFA 10: 1) (r ¼ 0.997,
P ¼ 0.043) in visit 4. In the majority of the studied nutrients
that showed changes across the visits the ratio of each
nutrient to total caloric intake of the nutrients does not
correlate (P40.05) with the total caloric intake. These are
b-carotene, vitamin D, a-tocopherol, folate, cobalamin, biotin,
sodium, iron, copper, manganese, chromium, cholesterol,
linoleic acid, dietary fiber and total sugar. Moreover, changes
in the ratios of vitamin A (r ¼0.58, P ¼ 0.0004), riboflavin
(r ¼0.42, P ¼ 0.02), pantotenic acid (r ¼0.47, P ¼ 0.006),
calcium (r ¼0.48, P ¼ 0.004), phosphorus (r ¼0.58,
P ¼ 0.0004), EPA (r ¼0.39, P ¼ 0.02) and DHA (r ¼0.34,
P ¼ 0.05), correlated with the drop in the total caloric intake.
Discussion
In this study we analyzed dietary data carried throughout an
extended period of time following the initiation of leptin-
replacement treatment in a group of leptin naive individuals.
In a previous report
1
we clearly showed marked weight loss
and decrease in body mass index following the initiation of
leptin replacement in these patients. Leptin replacement
brought about a transitory decrease of 50% in total caloric
intake, and after this initial drop the caloric intake gradually
increased and reached pretreatment levels, but weight loss
continued for several months in the context of increased
energy expenditure.
4
We showed here that the observed
reduction in caloric intake differentially affected nutritional
content. Our data reflects an increased percentage of dietary
fat intake, particularly on visits 3–5 (months 2–6). Our study
also showed a strong positive correlation between fat
percentage and linoleic acid in visit 3, and between fat
percentage and cholesterol, monounsaturated fat and oleic
acid (MFA 10:1) in visit 4. These strong correlations support
that, on those visits, the fat percentage increased due to the
Leptin replacement on nutrient choices
J Licinio et al
1860
International Journal of Obesity
45%
40%
35%
30%
25%
20%
15%
10%
Percentage of caloric intake
Percentage of caloric intake
Percentage of caloric intake
40%
45%
50%
55%
60%
65%
70%
35%
30%
25%
20%
40%
35%
30%
25%
20%
15%
10%
Aug-01 Oct-01 Dec-01 Feb-02 Apr-02 Jun-02
Aug-01 Oct-01 Dec-01 Feb-02 Apr-02 Jun-02
Au
g
-01 Oct-01 Dec-01 Feb-02 A
p
r-02 Jun-02
Carbohydrate
∗
∗
∗
∗∗
Fat
ABC
Protein
Figure 1 Fat, protein and carbohydrate percentages of caloric intake for the three subjects (a–c) across visits. The dotted vertical line indicates the beginning of
leptin replacement. **Statistically different from all visits, but visit 3 (Po0.05). *Statistically different from visits 6, 7, 8, 9 and 11 (Po0.05).
Leptin replacement on nutrient choices
J Licinio et al
1861
International Journal of Obesity
Table 1 Macro- and micronutrients at baseline (visit 1) and during the first year of leptin replacement
Mean Visit 1 V2 V3 V4 V5 V6 V7 V8 V9 V10 V11 Significant differences between pairs
of visits; P-valueo0.05s.d. Month 0 1 2 3 6 9 9
1
2
10 10 1/3 10 2/3 11
Macronutrients
Cholesterol (mg) M 547.24 475.29 399.29 185.48 373.42 241.45 251.16 287.48 203.26 402.34 426.62 1/4, 1/6, 1/9, 2/4, 2/9
s.d. 184.07 223.11 76.45 64.03 57.75 50.60 60.90 44.40 4.20 40.05 28.05
PFA 18:3 (g) linoleic M 1.09 1.05 0.60 0.33 0.53 0.45 0.42 0.49 0.36 0.45 0.49 1/4, 1/6, 1/7, 1/8, 1/9, 1/10, 1/11
s.d. 0.32 0.54 0.17 0.07 0.06 0.07 0.02 0.07 0.03 0.09 0.06 2/4, 2/6, 2/7, 2/9, 2/10
PFA 20:5 (g) EPA M 0.01 0.01 0.02 0.01 0.04 0.00 0.01 0.01 0.01 0.02 0.01 1/5, 2/5, 4/5, 5/6, 5/7, 5/8, 5/9, 5/11
s.d. 0.01 0.02 0.00 0.00 0.02 0.01 0.01 0.00 0.00 0.01 0.00
PFA 22:6 (g) DHA M 0.07 0.06 0.07 0.03 0.16 0.03 0.02 0.03 0.03 0.06 0.04 4/5, 5/6, 5/7, 5/8, 5/9, 5/10, 5/11
s.d. 0.02 0.05 0.02 0.01 0.09 0.02 0.01 0.01 0.00 0.01 0.01
Dietary fiber, total (g) M 24.32 23.41 11.52 9.22 11.75 23.51 21.75 19.51 20.65 22.25 31.31 1/3, 1/4, 1/5, 2/3, 2/4, 3/6, 3/11
s.d. 6.09 4.89 1.01 1.43 4.00 0.57 5.41 1.94 2.68 7.58 1.92 4/6, 4/7, 4/10, 4/11, 5/6, 5/11, 8/11
Sugar, total (g) M 157.26 137.79 65.25 62.21 86.25 124.87 138.33 134.94 107.87 130.16 193.40 3/11, 4/11, 5/11
s.d. 64.82 44.29 13.58 11.42 41.69 11.67 23.36 29.53 13.15 52.24 16.91
Vitamins
Vitamin A (IU) M 1115.54 1058.40 652.07 681.68 1204.32 1057.07 1148.89 965.81 1275.39 1098.71 1187.62 1/3, 1/4, 3/5, 3/7, 3/9, 3/10, 3/11
s.d. 306.35 45.50 254.93 24.92 155.56 34.47 170.94 34.33 94.09 61.10 97.12 4/5, 4/7, 4/9, 4/10, 4/11
b-Carotene (mg) M 2617.30 2051.35 1040.77 1023.28 3146.40 2635.22 1591.62 2226.73 4285.13 2541.86 2585.08 2/9, 3/5, 3/9, 4/5
s.d 1073.25 1084.45 541.02 664.26 370.07 793.77 539.72 439.83 148.92 268.74 757.92 4/9, 7/9, 8/9
Vitamin D (mg) M 4.74 5.39 3.74 1.26 3.33 3.10 4.06 2.78 3.28 3.60 2.69 1/4, 2/4, 2/8, 2/11, 4/7
s.d. 0.93 1.50 1.15 1.20 0.93 0.53 0.47 0.42 0.06 0.38 0.02
a-Tocopherol (mg) M 1.27 1.44 0.49 0.16 1.00 1.20 1.27 0.84 1.19 1.22 1.84 1/4, 2/3, 2/4, 3/11, 4/5, 4/6
s.d. 0.30 0.14 0.14 0.16 0.46 0.24 0.38 0.21 0.23 0.77 0.33 4/7, 4/9, 4/10, 4/11, 5/11, 8/11
Riboflavin (mg) M 2.99 2.91 1.62 1.50 1.91 2.52 2.65 2.52 2.22 2.36 2.90 1/3, 1/4, 2/3, 2/4, 3/11, 4/11
s.d. 0.72 0.90 0.20 0.18 0.26 0.42 0.03 0.17 0.21 0.19 0.26
Folate (mg) M 401.89 457.73 245.74 195.65 346.09 381.11 334.52 404.09 309.49 415.60 449.99 2/4, 4/10, 4/11
s.d. 104.42 128.52 46.57 19.16 88.80 104.03 46.13 31.77 21.02 43.63 35.33
Cobalamin (mg) M 6.45 6.72 3.84 2.39 4.77 5.54 6.38 6.37 5.65 5.34 6.78 1/4, 2/4, 4/7, 4/8, 4/11
s.d. 1.62 2.66 0.11 0.33 0.82 1.15 0.66 1.00 0.38 0.35 0.76
Biotin (mg) M 36.24 38.09 37.20 12.56 21.58 24.51 27.84 22.80 20.64 28.17 41.88 1/4, 2/4, 2/9, 3/4, 4/11
s.d. 7.50 10.08 10.38 3.20 4.11 4.00 1.92 2.59 1.00 5.29 2.09 5/11, 6/11, 8/11, 9/11
Pantothenic acid (mg) M 6.79 6.53 5.39 2.72 5.10 5.55 4.57 5.19 4.95 5.43 6.41 1/4, 2/4, 3/4, 4/6, 4/10, 4/11
s.d. 1.37 1.83 0.36 0.47 0.15 1.14 0.31 0.22 0.36 0.63 0.62
Minerals
Sodium (mg) M 3074.07 2638.79 1338.71 2136.70 1264.73 3094.05 3345.24 3710.79 3090.55 2583.32 4143.06 3/7, 3/8, 3/11, 4/11, 5/7, 5/8, 5/11
s.d. 1301.18 1033.03 181.73 263.38 121.98 372.22 869.90 662.10 324.75 123.00 265.05
Calcium (mg) M 1236.88 1147.72 658.72 844.82 772.59 1161.38 1067.31 1129.39 941.24 1013.63 1380.61 1/3, 2/3, 3/6, 3/11, 4/11, 5/11
s.d. 186.94 275.19 82.11 174.01 165.53 256.60 37.15 63.58 101.67 66.13 134.33
Iron (mg) M 17.33 15.18 8.52 6.30 15.73 14.25 16.86 14.48 13.53 14.93 16.72 1/4, 4/7, 4/11
s.d. 7.33 5.62 0.70 0.80 3.38 2.46 0.94 0.80 1.40 1.33 1.96
Phosphorus (mg) M 1637.05 1554.68 1012.58 847.94 1097.30 1445.82 1307.79 1444.69 1302.83 1337.82 1619.56 1/4, 2/4, 4/11
s.d. 396.30 480.64 16.62 81.09 26.06 247.51 88.77 199.16 77.87 99.62 167.23
Copper (mg) M 1.33 1.28 0.80 0.51 0.69 0.88 0.73 0.82 0.93 0.81 1.01 1/4, 1/5, 1/7, 2/4
s.d. 0.40 0.40 0.08 0.07 0.05 0.21 0.07 0.17 0.06 0.09 0.03
Manganese (mg) M 3.12 2.80 1.18 1.55 1.38 1.77 1.89 2.84 1.69 2.03 2.82 1/3, 1/5, 3/8
s.d. 0.77 0.86 0.21 0.36 0.12 0.36 0.38 1.21 0.10 0.33 0.07
Chromium (mg) M 0.05 0.05 0.03 0.02 0.06 0.06 0.05 0.04 0.05 0.06 0.07 3/11, 4/11, 8/11
s.d. 0.01 0.01 0.00 0.01 0.01 0.02 0.02 0.01 0.01 0.03 0.03
Abbreviations: DHA, docosahexanoic acid; EPA, eicosapentanoic acid; PFA, polyunsaturated fatty acid. Significant differences in the nutritional variables are shown in the last column on the right. When
pairs of visits are significantly different they are shown in the format ‘visit number/visit number’. Not included in the table: (a) no differences: saturated fat, monounsaturated fat, polyunsaturated fat, oleic
(monounsaturated fatty acidFMFA 18:1), vitamin E, thiamin, niacin, selenium and all but one amino acid. (b) Difference in one visit pair: linoleic (PFA 18:2), pyridoxine, vitamin K, molybdenum and
valine. (c) Difference in two visit pairs: vitamin C, potassium, magnesium and zinc.
Leptin replacement on nutrient choices
J Licinio et al
1862
International Journal of Obesity
increased dietary intake of foods that were good sources of
these four lipids. Analysis of dietary records and nutrient
content of consumed foods revealed that on visit 3, patients
ate foods higher in linoleic acid such as baked chicken and
mayonnaise. And on visit 4 they consumed more high fat
foods such as sausage, pizza, cheese, dairy creamer and
cooking oil. It is important to mention that these foods were
available during the entire treatment period, but the patients
only started to select them after the initiation of leptin
replacement.
This increase in fat percentage intake occurred at the
expense of a diminished consumption of carbohydrates.
Wetzler et al.
5
studied self-selecting rats on their choices of
macronutrients before and after leptin administration, and
found similar changes in the proportional intake of fat and
carbohydrates. One possible explanation for this finding is
that the increase in plasma leptin concentration inhibits
insulin secretion,
6
increasing insulin sensitivity.
1
It has been
proposed that such leptin-induced reduction of circulating
insulin hinders the metabolism of a high-carbohydrate
intake, so that high carbohydrate eaters would be compelled
to reduce its intake and increase the ingestion of fat to meet
their energy requirements.
7
Despite the caloric intake
decrease, the consumption of amino acids and the percent
protein intake did not change across the visits, and the
patients chose a dietary profile that preserved their necessary
amino acid load.
We also show that while ingestion of some macro- and
micronutrients did not change across the visits, ingestion of
several others changed after initiation of leptin-replacement
treatment. The majority of these changes do not correlate
with changes of total caloric intake, which means that they
are not due to the global decrease in caloric consumption,
but rather reflect a modification in the profile of food intake,
possibly due to a change in food preferences. These
preferential changes occurred with b-carotene, vitamin D,
a-tocopherol, folate, cobalamin, biotin, sodium, iron, copper,
manganese, chromium, cholesterol, PFA 18:3, dietary fiber
and total sugar. The changes in nutrient intake that could be
explained by the decrease in total caloric intake, being
correlated with changes in total caloric intake, were those
seen with vitamin A, riboflavin, pantotenic acid, calcium,
phosphorus, EPA and DHA.
Sample size represents an important limitation of this
study. However, the extremely rare occurrence of genetic
leptin deficiency prevents the study of more individuals.
These patients provide us with an unmatched opportunity to
understand the effects of leptin treatment on macro- and
micronutrient food choices.
Little is known about the determinants of nutrient
preferences in humans and it is unclear which factors
influence the choice of macro- and micronutrients. Pub-
lished work is mostly focused on the effects of different types
of nutrients on serum leptin concentration. In contrast, our
study assesses changes in food preference that occur when
leptin is administered. This unique data set supports the
concept that leptin influences distinct choices of nutrients.
These include specific changes in the intake of micro-
nutrients that corroborate the concept that leptin induces
at the macronutrient level a shift toward a higher percent
consumption of fats and a decrease in the intake of
carbohydrates.
Acknowledgements
We have been financially supported by NIH Grants
DK058851, DK063240, RR016996, RR017365, RR000865
and MH062777, and by an award from the Dana Foundation.
Amgen Inc. generously provided the r-metHuLeptin. None
of the authors have personal or financial conflict of interest.
References
1 Licinio J, Caglayan S, Ozata M, Yildiz BO, de Miranda PB, O’Kirwan
F et al. Phenotypic effects of leptin replacement on morbid obesity,
diabetes mellitus, hypogonadism, and behavior in leptin-deficient
adults. Proc Natl Acad Sci USA 2004; 101: 4531–4536.
2 Farooqi IS, O’Rahilly S. Monogenic obesity in humans. Annu Rev
Med 2005; 56: 443–458.
3 Ozata M, Ozdemir IC, Licinio J. Human leptin deficiency caused by
a missense mutation: multiple endocrine defects, decreased
sympathetic tone, and immune system dysfunction indicate new
targets for leptin action, greater central than peripheral resistance
to the effects of leptin, and spontaneous correction of leptin-
mediated defects. J Clin Endocrinol Metab 1999; 84: 3686–3695.
4 Williamson DA, Ravussin E, Wong ML, Wagner A, Dipaoli A,
Caglayan S et al. Microanalysis of eating behavior of three leptin
deficient adults treated with leptin therapy. Appetite 2005; 45: 75–80.
5 Wetzler S, Dumaz V, Goubern M, Tome D, Larue-Achagiotis C.
Intraperitoneal leptin modifies macronutrient choice in self-
selecting rats. Physiol Behav 2004; 83: 65–72.
6 Ceddia RB, Koistinen HA, Zierath JR, Sweeney G. Analysis of
paradoxical observations on the association between leptin and
insulin resistance. FASEB J 2002; 16: 1163–1176.
7 Poitout V, Rouault C, Guerre-Millo M, Reach G. Does leptin
regulate insulin secretion? Diabetes Metab 1998; 24: 321–326.
Leptin replacement on nutrient choices
J Licinio et al
1863
International Journal of Obesity
