Breastfed Baby Weight Gain

A breastfed baby’s weight gain is one of the indicators of whether or not the mother is producing a sufficient amount of milk.  New mothers are zealous weight watchers. While it’s not true that good weight gain is an index of good mothering, a baby’s weight gain may be some tangible reward for mothers for all those days and nights of breastfeeding, especially since breasts don’t have ounce measurement lines mothers can refer to.

Formula-fed and breastfed baby weight gain will vary because they grow at different rates. In general, breastfed babies tend to be leaner, which is healthier, especially in the long run (See 7 Ways Breastfed Babies Become Healthier Adults). Here’s a general guide to the growth and breastfed baby weight gain during the first year:

Breastfed baby weight gain (growth patterns)

• Weight gain of 4-7 ounces (112-200 grams) a week during the first month
• An average of 1-2 pounds (1/2 to 1 kilogram) per month for the first six months
• An average of one pound (1/2 kilogram) per month from six months to one year
• Babies usually grow in length by about an inch a month (2.5c.m.) during the first six months. And around one-half inch a month from six months to one year.

In 1992, Dr. Katherine Dewey, of the University of California at Davis conducted a study comparing the growth patterns of normal, healthy breastfed and formula-fed infants. Dubbed the DARLING study (for Davis Area Research on Lactation, Infant Nutrition, and Growth), the results showed:

• Breastfed and formula-fed infants grow at basically the same rate in the first few months.
• Between four and six months, formula-fed babies tended to gain weight faster than their breastfed baby peers, although growth in length and head circumference were similar in both groups.
• After the first six months, breastfed babies tended to be leaner.  Monitoring of breastfed baby weight gain vs. formula-fed baby weight gain during this study indicated that compared to their formula-fed friends, breastfed infants gained an average of one pound less during the first twelve months.

The extra weight in formula-fed infants is thought to be due to excess water retention and a different composition of body fat. Researchers in the study concluded that new standardized growth charts are needed that will reflect the different breastfed baby weight and growth patterns present in healthy, normal breastfed babies.

Variations in normal patterns of infant weight gain

Weight gain is determined by more than diet. This is why there is such a wide variation in normal patterns of infant weight gain. For example, babies with different body types due to heredity have different metabolic rates, and therefore burn calories differently.

• Long and lean babies (we call them “banana babies”) are hyper metabolizers. They burn off calories faster than the plumper “apple babies” and “pear babies”. Banana- babies are likely to grow more quickly in height than weight.  They normally plot above average in height and below average in weight on the growth chart.
• Apples and pears show the opposite pattern on the chart, usually showing gains in weight faster than height. All these patterns are normal.

Temperament also influences weight gain

• Mellow, laid-back babies tend to burn fewer calories and therefore gain weight more quickly.
• Active babies with persistent, motor-driven personalities who always seem to be revved up usually burn more calories and tend to be leaner.

Breastfed baby weight gain is influenced by the frequency of feeding

• Babies who are breastfed on cue and offered unrestricted feedings tend to grow faster.
• Infants who sleep next to mother and who enjoy the luxury of unrestricted night nursing tend to grow faster.
• Infants who are the product of “baby training” (parenting programs in which babies are fed on a schedule and forced to sleep through the night using variations of the “cry-it-out” method) often show delayed growth. Babies who are breastfed according to a parent-imposed and restrictive feeding schedule are not only likely to get less milk, the breast milk they get will have a lower level of fat and calories because of the longer intervals between feedings.

Various studies have shown that breastfed infants consume fewer calories and a lower volume of milk than formula-fed infants. This doesn’t mean their mothers aren’t producing enough milk. Rather, an indication that breastfed infants have an amazing ability to self-regulate their calorie intake according to their individual needs. This ability to determine for themselves how much they eat is probably one of the reasons infants who are breastfed are less likely to have problems with obesity later in childhood (See Breastfeeding Benefits from Top to Bottom).

For more information on breastfeeding, read: The Breastfeeding Book: Everything You Need to Know About Nursing Your Child from Birth Through Weaning

Dr. Bill Sears

Dr. Sears, or Dr. Bill as his “little patients” call him, has been advising busy parents on how to raise healthier families for over 40 years. He received his medical training at Harvard Medical School’s Children’s Hospital in Boston and The Hospital for Sick Children in Toronto, the world’s largest children’s hospital, where he was associate ward chief of the newborn intensive care unit before serving as the chief of pediatrics at Toronto Western Hospital, a teaching hospital of the University of Toronto. He has served as a professor of pediatrics at the University of Toronto, University of South Carolina, University of Southern California School of Medicine, and University of California: Irvine. As a father of 8 children, he coached Little League sports for 20 years, and together with his wife Martha has written more than 40 best-selling books and countless articles on nutrition, parenting, and healthy aging. He serves as a health consultant for magazines, TV, radio and other media, and his AskDrSears.com website is one of the most popular health and parenting sites. Dr. Sears has appeared on over 100 television programs, including 20/20, Good Morning America, Oprah, Today, The View, and Dr. Phil, and was featured on the cover of TIME Magazine in May 2012. He is noted for his science-made-simple-and-fun approach to family health.