Mum's diet shapes a child's future weight

By Ellen Connolly
January 27, 2008 01:00am

AUSTRALIAN scientists have made the world-first discovery that a pregnant woman's diet determines whether her baby grows into a fat adult or a skinny one.

The research suggests women who are overweight before they fall pregnant, and during it, may condemn their children to a life of overeating and obesity.

It reveals that a mother's diet during pregnancy affects the baby's brain circuits, determining appetite and energy expenditure in their offspring.

"This suggests that mothers should think twice about overindulging, or using the excuse that they're eating for two during pregnancy," University of NSW professor Margaret Morris said.

Pre-natal period programs a child's future appetite

Unlike previous studies, the groundbreaking work highlights the pre-natal period as a critical time for "programming of post-natal and adult appetite".

It found that even before a woman falls pregnant, she is potentially "programming" a child's future appetite.

"The major finding is the dramatic increase in body fat in offspring of overweight and obese mothers," Professor Morris said.

Mothers fed a high-fat diet had offspring that were heavier, with more body fat and altered appetite regulators in the brain, meaning they overate, she said.

The results are supported by a study published in the British Journal of Nutrition last year. It found that mothers who eat junk food during pregnancy may produce children who crave the same foods.

Professor Morris will present her findings at the Australian Neuroscience Society conference in Hobart this week.

She said the study was particularly relevant, given that about 30 per cent of mothers enter pregnancy in an overweight or obese condition.

Study mated overweight female rates with healthy males

The study was conducted using overweight female rats who mated with healthy males.

The females continued to be fed a high-fat Western diet during and after pregnancy, Professor Morris said.

"The mums were overeating for that whole period. We found the offspring were a third heavier than the rats fed a low-fat diet," she said.

Professor Morris said the brain pathways regulating appetite in rats were similar to those in humans, suggesting similar trends could be expected in people.

Sydney University nutritionist Dr Jenny O'Dea said it had become "quite well accepted" that a woman's diet during pregnancy impacted on the fetus.

"We also know that obesity during pregnancy more often than not causes gestational diabetes and high blood pressure," Dr O'Dea said.

Pregnant women should not 'eat for two'

She said that although nutritional needs were high during pregnancy, women should not be "eating for two".

Professor Morris studied mothers who were already overweight before they fell pregnant. The experiment results also found their offspring were showing signs of developing diabetes at a young age.

The findings are particularly relevant for overweight mothers, highlighting the importance of maintaining a normal weight before and during pregnancy.

Further research will examine how methods of intervention during breastfeeding can reverse bad nutritional habits and overeating.

Susie Burrell, a pediatric dietitian at The Children's Hospital at Westmead, said the study sent a powerful message to women planning to fall pregnant.

"They need to get their weight under control before conceiving, and those who are pregnant need to have minimum weight-gain during pregnancy," Ms Burrell said.

She said an increasing number of women were overweight before they fell pregnant, creating a "snowball effect".

"Their babies are more likely to have a high birth weight. This then leads to lifestyle diseases such as type 2 diabetes and heart disease."

Future Foods? American Fitness, Nov-Dec, 1991 by Mary Hubbard

Pfizer, Inc. has submitted a petition to the Food and Drug Administration (FDA) for the approval of its sweetener called alatame. It is 2,000 times sweeter than sugar and is formed from two amino acids (the building blocks of protein) just as is aspartame (the chemical name of NutraSweet). It is reportedly more stable than aspartame and may thus be used in baked goods as well as beverages.

Sucralose

A subsidiary of Johnson & Johnson, McNeil Specialy Products Company, has submitted a petition to the FDA for approval of a sweetener which is made from sugar, but is 600 times sweeter. Because it is made from sugar it has excellent stability even at high temperatures so it is suitable for use in a broad range of foods including beverages, baked goods, chewing gum, dairy products (like ice cream), syrups and even tabletop sweeteners you use to sweeten your coffee or cereal.

Left-Handed Sugar

The perfect sugar substitute probably doesn't exist, but left-handed sugar (L-sugar for short) sounds very close. This is a substance with its molecules arranged in the mirror image (much as your left hand is the mirror image of your right hand) of regular sugar. The big difference is it can't be digested and absorbed by your body because our digestive systems only "fit" the regular sugar arrangement. It would be like trying to put your left hand into your right glove. And if it can't be digested and absorbed it will pass right through the body so it can't supply any calories. L-sugar supposedly looks like, cooks like, and most importantly, tastes like regular sugar.

Now the artificial fats enter into the picture. Fat of all kinds (solid, liquid, saturated or unsaturated) is a concentrated form of calories. Fat provides nine calories in only one gram (about the weight of a small paper clip), whereas protein or carbohydrate each provide four calories per gram. And evidence is building dietary fat is more easily converted to body fat than are either carbohydrate or protein. So if we could find a way to decrease the fat in our diets (without making any sacrifices, of course), then we could reduce our calories even more drastically than by using sugar substitutes. Imagine fat-free french fries and rich ice cream with less than half the calories.

Simplesse

This artificial fat is claimed by the NutraSweet Company to be the first and only all-natural fat substitute. Simplesse is made by cooking and blending milk and/or egg white protein to make a creamy fluid with a texture so like fat it fools the tongue. It is completely digestible, but substitutes one or two calories of protein for nine calories of fat. Total calorie savings in products will range from 20 to 80%. However, Simplesse has some limitations. Frying or banking will cause Simplesse to gel and lose its creaminess which limits its uses. Simplesse will probably not be sold for home use, but will be sold to food manufacturers as an ingredient in sour cream, cream cheese, margarine, yogurt and ice cream. Simplesse has already received approval by the FDA. In fact, Simple Pleasures[TM] ice cream, which utilizes Simplesse, is currently making its way across America. Its level of acceptance will determine if more products using Simplesse are in our futures. One attractive possibility is the combination of Simplesse and NutraSweet in the same product, a creamy sweet frosting, perhaps? After all, the NutraSweet Company owns the patent on them both.

Olestra

Proctor & Gamble has been researching "olestra," on a fat-sbustitute made from sugar and vegetable oil. This substance is calorie-free-because it is not digested or absorbed by the body. Research shows olestra may lower the absorption of cholesterol from food in our digestive systems. This is a definite health bonus, but one that has caused the FDA to demand even more intensive research on its safety be conducted before it can be approved. Fat using 100% olestra for a cooking oil is not feasible as it causes diarrhea, so it is blended about 50-50 with regular cooking oil. It is said to look, cook and taste like regular oils. It is not broken down by cooking temperatures and can be used in baked goods, fried snacks and frozen desserts.


As revolutionary as these new products are, we need to put these possibilities into perspective. Studies have shown even with the availability of artificial sweeteners (and Americans are guzzling millions of cans of sugar-free soft drinks each year), we have not really reduced our overall calorie intake. It seems we just eat more of other things to make up for the ones we have given up. So remember, a healthy, nutritious and yes, delicious, diet is not a function of any individual food or product like artificial sweetener or artificial fat. It is determined by a diet rich in a variety of fruits, vegetables, whole grains, lean meats and low-fat dairy products.